Added 8 Feb 2018. At about 4:20 in the video, I called the Interstate SRM-24 battery a "deep cycle battery." It is not a "true" deep cycle battery. I should have called it a "dual purpose battery." There are some very interesting comments about the connection of the trailer's white ground wire to the negative post of the left battery instead of the right battery, so I will address that in some detail in this post. First, as I have previously posted, there would be no harm in connecting the white ground wire to the negative post of the right battery. Electrically, there is no practical difference between the two connection points; here is why. The two negative battery posts are connected by a 1 AWG cable that is 24" long; its resistance is 0.25 milliohms, which is .00025 ohms. The internal resistance of a lead acid battery (such as those used in the video) is at least 50 milliohms when the battery is new and rises to as much as 1 ohm as it ages. So, there is at least 400 times ((50 + 50)/.25) as much resistance in the two batteries as there is in the black cable. Looking at it another way, the white wire is 12 AWG and is also about 24" long; its resistance is 3.2 milliohms, which is 12.8 times as much as the 1 AWG black cable. So, if I were to lengthen the white wire just 2 inches, I would have added more resistance with that two inches than the resistance of the entire black cable. Would that have had any practical effect on the batteries? No... just as the .00025 ohms resistance of the black cable has no practical effect. If you have a different opinion, that's fine. We will just have to disagree. Thanks for watching the video and please subscribe to the channel. I will add a solar charging system in a future video.
@@YAYA-bv7po very simple. It basically goes in between the neg cable or pos cable (depending on which person you are) from your trailer. Bolt it on somewhere n ur done.
@@YAYA-bv7po It is simple to do. I mounted my cutoff switch in the positive lead on the side of one of the battery boxes. That way, I can turn the power on and off the entire RV from the battery location. Thanks for watching.
@@miztrusa Thanks Mike. It's better to put the cut off switch in the positive side because the steel frame of the RV is often used for the negative side.
I watch TH-cam videos all the time. I must say it's extremely rare to find someone who speaks clearly and is precise in their instructions. This video made me enjoy your experience immensely. Thank you for the time in making this video.
This was a great video demonstration for a complete novice like myself. I really appreciate his slow and methodical demonstration that was so very helpful to me and I'm sure many others. Thank you sir!!!
hello from the rainy warm ozarks im not chuck! while i was preparing my wakeboat for winter , i noticed the battery connections were secured just like yours!!! my moomba 24ft. wakeboat built in maryville,tenn. battery connections came from the factory just like yours!! i appoligize it took so long to respond, but my internet at my fithwheel rv is poor. i went up to the bathouse and laundry to download this. tight lines and grace be with you!
Wow!! Thanks, INC! Watching this video, I realize that I am missing the Positive cable from my engine battery to my house batteries!! No wonder the darn house batteries don't charge when I am driving!! I can't wait to climb under my van tomorrow to locate it!! You are PURE GENIUS! Thanks soooo much!! Happy trails to you and your wife!!
Great advice to stretch out battery power! I had an old Tioga with a mish-mosh of batteries and because they didn't match up too well the whole bank drained out pretty fast. Trying to get your battery specs to match up will help even out charging and discharging. Thanks for posting this up.
Great video, I would consider placing the negative connection to the trailer on the negative of battery #2 so that the load comes out proportionally even preventing discharging one battery then going to the next one.
Charles in Charge...Food for thought. Your typical true deep cycle (not dual purpose) 6v golf cart battery has 225ah, whereas your typical 12v dual purpose deep cycle that many people use has around 75ah. Tip: you only have 50% of that usable charge, or 37.5ah. If you draw it down more than that, it will damage the battery and severely shorten its lifespan. Two 12v in parallel will stay 12v but have 150ah, or 75ah of usable charge. Two 6v with 225ah hooked in series will become 12v but stay at 225ah, or 112.5ah of usable charge. If you build a battery bank of four 6v 225ah two pairs in parallel (6v 450ah) and then series the two together it will be 12v 450ah with 225ah of usable charge.
In principle, I agree with your analysis, although even deep cycle batteries should not be discharged below 12.5 volts. Thanks for watching and for the "food for thought."
I've not read all the comments and maybe you've changed from a year ago, but so that you get better flow thru the batteries and prevent a dead cell you might have put one or the other connections on the other battery, This way your flowing from both directions thru the entire battery bank. This is a new style of connection that most everyone is changing over to now.
Thanks for watching and commenting. Please see my pinned comment at the top of the list. You are certainly correct that many people are doing as you suggest. If you haven't subscribed, please do so.
Hi Chuck your right am thanks for a fast reply I did what you said used three this way heavy cables like you say it works really well thanks for sharing your knowledge
Thank you! I just found your channel because we are getting two batteries today to replace our one old battery in our 5th wheel. Your video is very well made. I saw you have some Bible videos so I subscribed.
I have dual batteries in my truck and in the camper..and I installed a 6000w inverter to only run refrigerator while travel and turn my LP off now then throw a transfer switch to switch it back to site power, very happy with this install..
Looking for buy BATTERY in USA ! Found a really good deal on these Batteries at www.bigbattery.com/deals. Use the discount code { Lithium5 } to save an additional 5% discount.
Thank you. Enjoyed the video. Easy to follow. I had a sailboat with two deep cycle batteries. They would charge from shore power when connected or from the alternator when under power. Very similar to my camper? Charging while plugged in, and charging through the truck alternator while travelling. On the boat I had a battery isolator. I was told it was very important to balance the charging of the two batteries. Would this apply to two batteries on a trailer? I’m trying to expand my off grid camping power and am doing my research.
Well done, nice and simple. Like 2 water butts connected, drain water from the tap end one will drain both at the same time. not just the tap end water butt.
I had the 2 batt setup on my RV for years. I always had one batt wear out before the other. A mechanic i know that works at Lockheed Martin told me to run the RV wires one from each batt instead of both from one and I never had another issue with 1 batt going bad before the other.
@@ImnotChuck. what is the benefit of 2 six volt batteries vs what you had? I am in the process of getting batteries for my travel trailer and I am having a heck of a time deciding which way to go! I am NOT a mechanic, nor do I have much experience with electrical. I feel like most people making these videos are speaking far to technically. you seem to explain everything very easily.
@@paullywalnutz Thanks Paul. Assuming equivalent size batteries, putting in two batteries instead of one doubles the amount of power storage you have available. That is true whether you put in two 12 volt batteries in parallel or two 6 volt batteries in series. Good deep cycle batteries are more readily available in 6 volt versions (largely because of the electric golf cart market.) For that reason, I am now running two Trojan T-105 6 volt batteries in series. Of course, since I made this video, lithium iron phospate batteries have come on the scene, and are the best choice if you can pay the price. When my currect batteries are exhausted, I will probably go to LiFePO4.
@@ImnotChuck. THEN YOU WILL HAVE TOO BUY A POWER CENTER CAPABLE OF CHARGING LITHIUM AND A DC TO DC CHARGER FROM YOUR ALTERNATOR TO THE CENTER. NOT FOR ME.
Great job on the video, you made it simple and easy to fully understand. However, I would suggest an add-on to the video and that's to be carful with wearing a watch, especially one with a metal band and/or a metal clasp. I had an incident where my watch touched the positive lead casing a burn to jump to the opposite side of my wrist. Apparently the current went right though my wrist. Believe me a 12v battery can really give you a jolt.
It would be better to remove any metal from your hands. The problem is not so much shock as it is burns. Thanks for watching and commenting. Please subscribe if you haven't already.
Hi Peter. Thanks for watching and for your question. For the answer, please read my comment pinned to the top. The short answer is that it doesn't matter as long as large diameter cables are used to connect the two batteries in parallel.
Nice video not Chuck very informative and kept things simple. One tip though, if you connect the trailer wires to different batteries (positive to battery 1 and negative to battery 2) you will get longer life out of your batteries. Wiring both to one battery the trailer will draw off that battery first weakening it over time. Batteries in parallel are only as strong as the weakest battery. Hope this makes sense.
I understand that most people have been taught as you describe. However, I don't believe that it matters at all. See my comment pinned to the top for my reasoning. Thanks for watching.
The battery store I use recommends this, Hook the positive cable from the trailer to one battery and the negative cable from the trailer to the other. This ensures you get equal drawdown from each battery.
Hello, and thanks for watching and posting. Please read my pinned post for a technical explanation of why I don't believe that is necessary. It doesn't matter which way they are connected.
@@ImnotChuck. Not in anyway saying you are wrong in the way you connect. As a matter of fact, they also recommend when you replace one battery, you should change both with two new units. I went this route on my IPod and have never had an issue
@Jack Smith I would be changing battery stores if I were you, it is complete nonsense to suggest the only way to get equal drawdown is by attaching the pos to one battery and neg to the other. Equal drawdown is attained EITHER that way or using both terminals on one battery when they’re connected in parallel.
@@steviebee1989 you need to learn how to completely read a statement. Then think it through. No where did i say this was the only way. I was SIMPLY stating that this is another option. Which, by the way is supported by others posting to TH-cam and some Rv retailers.
@@steviebee1989 You are Absolutely Incorrect 💯%!! They will not draw down equal. They will eventually equalize after you turn off the draw. And the primary has to overcharge to push power to the secondary battery. I managed an Interstate Batteries for 2 years and was an assistant manager for Batteries plus ➕ for 3 years 👍
Hello, very informative video as well as the detail of your pinned comment. Thank you. My trailer is about a year old and I am looking to upgrade my cables as I do have a problem with one battery discharging faster than the other. I’m guessing it is because the dealer only used 8 ga wire to connect the two together. I even switched the batteries and the way it’s wired it still discharged the one with the main coach cables first. Can you give a suggestion on running new cables to the fuse panel? Currently it’s not marked but looks to be 8ga maybe 6ga at the most. Is there any disadvantage to going too big, or a point that there is no addition benefit to a thicker ga? Thank you.
8 gauge wire is sufficient from the batteries to the fuse panel and is actually better than the 10 found in most travel trailers. My suggestion for very heavy cables is only to connect batteries in parallel. It could be that one of your batteries is just weaker than the other, and there isn't anything I know to fix that. Thanks for watching and for commenting.
I got rid of my single 12 volt battery and bought two 6 volt batteries, ran them in series and now have 12volt with about an extra 185 amp hours more than two twelves ran parallel like you did.
Using two six-volt batteries in series is preferred by many people, and is a good method. However, the specific amp hour capacity in either case depends upon the batteries chosen. Thanks for your comment; please subscribe if you haven't already done so.
I am preparing to upgrade my RV to two house batteries. Instead of using two Interstate (not true deep cycles) 12volts in parallel, I'll be using 2 T105 Trojans 6 volts in series. My personal research has led me to the conclusion that because Trojan makes only deep cycle batteries and is the gold standard for the entire golf cart industry, and is almost the same cost as Interstate, is a far better buy. 2 6v Trojan T105s will give me 100ah at 12v. I will be adding 2 more in a couple of months when I install my solar system. That will put me at 200ah at 12v. For now, I am using a Predator 3500 Generator/Inverter when boondocking.
John K, You have obviously done some research about batteries, and I like your plan. I don't have any personal experience with the T105, but I know that Trojan makes fine products, and the specs on the T105 look good. I especially like that you have chosen a flooded lead-acid battery; I will go into some detail about that in the next video. Thanks for your comment; please subscribe if you haven't already done so.
Good video, thank you. However, I have to agree, the negative wire from the trailer should have been connected to the negative post of battery number two. It would help both batteries to receive equal use and therefore wear equally.
No, I didn't modify the battery boxes, but the boxes are different brands, and slightly different configurations. Thanks for the question and for watching.
Great video. I have a 1 year old battery. Can I add another battery parallel even though it’s 1 year old? Would 4 gauge cable be ok? What size cable do you recommend? Thanks
Larger diameter cables are better, but four gauge will certainly work. And generally, it's better for batteries in parallel to be "mates" in terms of age, etc., it's acceptable for them not to be. Thanks for the nice words and for watching.
Quick question, when you want to charge the batteries with an charger, how do you connect the leads, just to the pos and neg to one battery or pos on Batt A and Neg on Batt B?
Good question. The answer is to connect the positive lead from the charger to either of the positive battery terminals, and the negative lead from the charger to either of the negative battery terminals. Because the batteries are in parallel, it's easy. Thanks for watching.
Hi, when adding a second battery, does it need to be the exact same brand or specs. I have a second 12v deep cycle battery but it's from Costco and the one in our rv is an Interstate 12v deep cycle. Thank you very much.
Yes, both batteries should be the same age, brand, and specifications for optimum performance and life. Otherwise the newer or stronger battery will do more work and age faster. Thanks for watching.
Make sure both batteries have the same date codes so that there is little difference in the capacity of both batteries. If one battery is older than the other, it may have a lower voltage/current capacity causing the two batteries to "fight" against each other, and may cause early failure of both. I found this out when I paralleled two batteries in my Jeep, one original, and another 4 months older. Try to pick both batteries off the shelf with the same, latest date codes. Look in the back of the shelf for the newer batteries, as the seller rotates the older batteries towards the front so they get sold before they get too old. ALWAYS keep both batteries shiny clean, because road dust has iron rust powder (from rusty cars and trucks) in it causing a high resistance path between the positive and negative posts, draining the batteries even while not being used. I use Vaseline to coat the posts to keep corrosion from starting.
Nice video, thanks for explaining everything so clearly. I'll actually be able to do this. We take long trips through the desert and next time would actually like to keep the refrigerator running. Can I apply this same technique if I want 3 aux batteries? is it safe to have 3?
Thanks for the positive comment Michael G. Adding a second battery will effectively double the time you can boondock. And a third battery is completely safe and done in exactly the same way. I have another video planned that shows how to add a couple of solar panels to the system; solar panels are great in the desert.
Hi, as many others have said, there is a problem with connecting the output cables ( and input cables, for that matter ) to one of the two batteries. You are right that the resistance between the batteries is negligible but if you see what the battery manufacturers say, it is always to connect from the positive of one battery and the negative of the other, with both batteries connected in parallel as you have. The reason, I believe , is the drop in internal resistance as a lead/acid battery discharges, making one battery work harder than the other, so to speak. It seems intuitively correct the way you have done it, but the manufacturers say differently.
It's not a matter of intuition; it's physics. The manufacturers who recommend differently do so because they don't want to bother explaining the science involved, so they take the easy way out. As I have said, there is nothing wrong with connecting parallel batteries with one connection at the positive of one battery and the other at the negative of the other battery, but there is nothing to be gained by it, if heavy gauge cables are used between the two batteries.
You are only considering the physics external to the two batteries, they are not a perfect electrical supply but a collection of chemical elements which act together to produce electricity. In a perfect system, you would be right as both batteries are effectively connected to the same inputs and outputs but in practice it's very different. I only teach physics up to students of 16 years , higher than that I am only a biologist, so I rely on the experts on this. All the manufacturers in the USA, Europe and Australia give the same advice about connecting across the batteries, as do the suppliers of chargers and inverters. If you're not a heavy user of batteries then it won't make much difference but in heavy use it will make a real difference to the working life of the set up.
As a life long engineer I must agree with Crusty. A U.S. Battery representative explained using a terminal from each battery as outputs enables greater equalization on draw down and recharge. There is, as proved by certified testing an increase in the loss of power using the terminals from only one battery in a 2 battery set. Basically, over the life of the battery under normal circumstances, connecting them as shown in your video reduces the life of the output battery versus the second battery. It's measurable over the life of the battery. There are other reasons why every single battery manufacturer recommends using one terminal from each battery as outputs.
Thx Crusty...I have watch several of these videos and am amazed how many connect the house connections to the SAME battery instead of using the other battery. Seems about 50% are doing this. Yes, it seems it would not matter but i think i will stick to using the positive of one battery and the negative of the OTHER battery just to be safe. Then i will be Will Prowse approved, lol!!.
I thank you for watching and for the nice compliment. There is lots to know about an RV, and most of it is easy to learn...after you have done it once or twice.
Chuck, you are using 1 gauge wire for the "Jumper", is that the requirement? I have been told that as long as the Jumper is a heaver gauge than the wires coming from the Trailer, that is fine, what say you?
Larger is better because I want to avoid ANY significant voltage loss between the two batteries, and thus essentially make the two batteries perform as one. That will eliminate one battery discharging a different rate from the other. In addition, some trailer manufacturers use smaller wire than they should to go from the battery to the converter, which makes the problem even worse. Please read my post pinned to the top of the comments for more info. Thanks for watching and for commenting. Please subscribe if you haven't already done so.
nice vid.. unfortunately you took out a worthless battery, and replaced it will another worthless battery.. (not deep cycle) get a couple of t-105s or so. I found the GC2 size (golfcart size) battery box like you use at Walmart online. You can get a good 6v GC battery at Costco for $93 dollars each, and have a true deep cycle system. you use a nice size cable between the batteries and use the same too small cable to RV.. that's where you need the size more than between batteries.. and it does matter a bit on where you connect the leads,, one to left bat positive and other to right bat negative to keep the pull the same between batteries.. keep up the good work.
Thanks for watching and for your input. As to the relative worth of dual purpose batteries versus true deep cycle batteries, I agree that true deep cycle batteries are better, but I am not sure whether they are sufficiently better to justify the price increase. I am now testing some cheap dual purpose batteries to see how they perform with proper maintenance and correct charge and discharge patterns. So far, they are doing well, but I am only eight months into the test. I will be doing a video on that experiment in the future. Please subscribe if you haven't already.
Is the heavy cables between the two batteries necessary? The feed wire for the trailer seems much smaller, so couldn't you size the wires between the two batteries to the same size as the trailer feed wires?
Hi. Thanks for watching. It does seem like smaller wires would be okay, but the purpose of the large wire between the two batteries is to keep the batteries equalized. If not, then the weaker battery will discharge faster and fail much sooner.
There is Absolutely no requirement for the heavy cables. Even with a everything on in the trailer you would never draw enough amps to need it. And the Proper way to hookup the trailer wires to the batteries is Positive to one battery and Negative to the other. That way the batteries will Charge and Discharge as a pair. The way you have it by only hooking up to the one leaves the batteries to feed off each other. And if you are looking for longer run time and Amp Hours your better off with 2 6volts. Golf cart batteries are the same footprint as the group 24 just 11/2 inches taller.
@@jamesglenn520 If you would read the scientific explanation that I wrote and pinned to the top of the comments, you would have the facts, and the correct answer to both your comments. The short, heavy cables connecting the two batteries eliminate any significant difference in the resistance due to the connection position of the cables. Your post is just one of many repeats of an old wive's tale told by shade tree mechanics with no basis in science. Thanks for watching and for posting.
Chuck, am old school, love marine deep cycle..Have 4 105ah…These are at home for emergency Only..they serve me well…But for rv, etc, where your constantly taking them down to low limit, Even past 50%, which I have when I had an rv years ago with young kids, gets cold at night Was forced to run past 50%…they were luck to last a season…You should really think about Going with lithium..long run it will pay.. Thanks for the vid.. Dennis
Hi Dennis, and thanks for watching and commenting. Of course you are right, and I am thinking about LiFePO4. I am a ham radio operator and am planning on putting my HF rig in the trailer for our next trip; it will be a big drain on the deep cycle Trojans FLA's that I have now. But $2 grand is a lot to spend for two batteries. :-)
If your trailer was built with just one battery, wouldn't the charging system charge at a single battery rate (??). If you add a second battery, should the recharge rate be changed?? I have a single battery on my trailer and when it's plugged into shore power, I believe the charging rate to the battery is just over 13 volts. Would that charging rate we okay for "two" batteries?? Thank you :)
Good questions! The voltage of two 12V batteries in parallel does not change, so the charging voltage does not change either. In addition, the charging current (measured in amperes) is regulated by the batteries; they will take only as much as they need (up to the maximum that the charger can supply.) However, it will take twice as long to recharge two "hungry" batteries as it does to recharge only one. Thanks for watching and for the thoughtful questions.
Hi, and thanks for watching and posting. Before you buy more batteries like the ones in the video, consider going to a true deep cycle battery like the Trojan T-105.
Hiya, reading the voltage on a battery is no indication of the state of the battery you have to use a load test which is a dummy load and a meter that indicates the state of the ability to take and hold charge. Here in the U.K. most garages will have a tester and will do it for free. Don't be to surprised by the hefty spark when doing the test, this is normal. Batteries are not cheap and disposing of a healthy one when you don't need to is expensive. If they are not sealed cell units make sure the distilled water is topped off to the correct level before testing as a faulty cell may boil. You don't need to earth the second battery as this will form an earth loop, which in extreme cases may be a problem, one negative connection is sufficient as is one positive lead. Happy camping...
Thanks for watching and for commenting. Testing a battery under load is common here in the US, however load testers are less accurate than measuring the voltage with no load and checking the specific gravity. In fact, load testers are seldom adjusted to the size of the battery under test and can overload batteries during a test and permanently damage them. I have a battery load tester that I designed and built, but seldom have any reason to use it. When you have time, watch my two videos on specific gravity testing. As you will note, it is not a good idea to add water to a battery just before checking the specific gravity because the water will not be properly mixed in the electrolyte and the readings will be incorrect. Topping off cells with water after testing is proper. As to your comment about "earthing," electrical systems in RVs are never connected to earth ground except when using "shore power." I am sorry my reply isn't more positive, but I have studied lead-acid batteries extensively and formed my own opinions. Thanks for yours.
Good video can i hook up both batteries like this for my boat 12 volt trolling motor, and how do I charge the batteries when there hooked up parallel like this
Yes, trolling motor batteries work the same way, and are charged just as if there was only one battery... just connect the charger positive anywhere on the batteries' positive, and negative to negative. Thanks for watching and posting.
I was not familiar with that battery, so I googled it. It seems to be a 12V LiFePO4 battery, so if that is correct, there is no reason you can't wire them in series. Of course a series connection will result in the voltage being doubled to 24 Volts which means that all the DC equipment in your travel trailer will need to be 24V devices, which doesn't sound right to me. If you have 12V devices, you will need to wire the batteries in parallel in order to keep the nominal voltage at 12 Volts. Thanks for watching.
@@ImnotChuck. Thanks I'm Not Chuck, I googled 24 volt converter chargers and I think they bring the voltage back down to 12 volts when the batteries are connected in series. Does this sound right to you? I want to build a powerful 24 volt system, I've been watching Will Prowse speak about 24 volt systems. TKS for your honest opinions.
I noticed you wisely used a ratchet wrench with a short handle. Smart. that way y0u reduce the chance of accidentally "bridging" the terminals and zapping yourself.
Thanks for watching and commenting. I find lots of uses for that little ratchet; the handle is hinged to the head for times when there is very little room available. The only problem is that it doesn't provide much leverage.
Can't go wrong with an Interstate Battery! Last fall I had my camper plugged into the house, while I was doing some cleaning and getting it prepared for winter and forgot about it and thought nothing of it. My battery was 4 years old. Well ....3 or 4 days later it exploded! I called Interstate Corperate to find out why? They told me that it keeps charging when you are plugged in, and here I thought it only charged when going down the road being towed. Well guess what? Interstate brought me out a brand new battery! I didn't even ask for them to replace it, I was just wondering how to prevent another battery from exploding in the future! Customer service like THAT is why I will always buy Interstate from now on!
The Ac/Dc converter of your trailer should have cut back or cycled the charging off when you were plugged into the house. The battery may have exploded to an overcharging failure of the converter.
Ive found that a lot of devices I have in my home, such as my cable internet modem, the wifi router, and the cell-spot router for T-Mobile, all are connected to the 110AC, and each one converts it with the big plug that goes into the wall, (Switching power supply AC>DC0 all run 12v at the device itself. I purchased a Marine battery, deep cycle, a cheap 12v solar panel for RV's, and have hooked each one up, by cutting the plug off of them, and connecting them directly to the 12v batter. I did it this way, because if I purchased an Inverter, and plugged the devices directly into the inverter, I would be then converting DC from the solar panel, to AC in the inverrter, which then would be converted back into DC with the plug. This makes it roughly 60% more efficient after I did the math.
This is how i planned on doing this, my question is. Do you need identical batteries? I.E. say one is a group 24 with 500cc and 600c and the other say a 27 or still a 24 group with 600cc and 750c. Reason i am asking is i will be converting over to interstate RV batteries but currently, i have an Oreily deep cycle that has been good but i want to upgrade. However, this battery is still in good shape no sense in tossing it. once it dies ill get another interstate identical to it.
Both batteries should be identical in both size and age, if possible. Otherwise, they will discharge at different rates, and the capacity difference will increase over time. Before you buy Interstates, I would suggest you consider true deep cycle batteries such as the ones made by Trojan.
Interstate Batteries are imported now and Trojans are also. So the quality is not what it was years ago. If you have a Batteries ➕ bulbs in your area the DURACELLS are the best 🇺🇸 made available.
Battery that are connected in parallel. It's better to connect positive cable on one battery and negative cable on the other. Then you drain both battery equally. Be sure to have same length on both cables between the batteries. Just a tips.
Thanks for watching and commenting on the video. Please read my my post pinned at the top for an explanation of why I do not accept that there is any reason to wire my batteries differently from what I showed in the video.
@@Farmer2492 What you see on the video is a parallel configuration. If you were to hook the two 12V batteries in series, then you would have 24V. Thanks for watching.
I'm not Chuck, I have another question. I have enough room on my trailer tongue for three batteries, can I connect three batteries in parallel for more electrical storage?
@@ImnotChuck. Thanks, I'm not Chuck, just bought a bumper pull, I'm taking a boon docking zig-zag route, (six weeks travel) to the coast of Oregon, from Weatherford Texas and need all the juice I can store, (powered by a Champion Gen). I'm subscribing to your channel now. Good luck.
I put a 80w solar panel and cheap mppt controller on our one 110a battery - max charge is about 5 amps - the beauty of this approach is that the battery seldom falls below 1/3 empty so it should last 5 or more years - if we were doing it again we would use the new thin solar flexible panels that just stick to the roof
Keeping your battery at 66% charged or higher is good for its life expectancy. In an upcoming video, I will present some graphs that show that 80% pays even more dividends. A lot of people don't realize that a 12V battery that is down to 10.5V is considered completely discharged. Thanks for your comment. I hope you also subscribed.
We used this www.ebay.co.uk/itm/5A-10A-12V-24V-MPPT-Solar-Panel-Regulator-Charge-Controller-55V-Input-DC-USBBR/292425975504?hash=item4415f246d0:m:ml_V81nPz1Cjm87V-I67Jng It float charges at 13.8volts & wiring is 12gauge silicon insulated used for RC - its been on 2 years now and has been completely trouble free - The USB ports get a lot of use charging peoples phones especially at music festivals!
I don't have any direct experience with a pop-up and wire colors vary from one RV to another. It should be in the manual that came with your trailer, but if you don't have a manual, look at the manufacturer's web site and you should be able to find one there. Sorry I can't help more, but I would be guessing, and that's a bad idea. Thanks for watching and please subscribe.
Nice video only think as far as I know you should have put the ground from the RV on the other battery . It will work but will drain the power more from the left battery .
As Already mentioned, the ground must be connected to the battery that you are not taking the live feed from, this will ensure you get equal discharge of both batteries.
Thanks for watching and commenting. I have addressed this issue many times; please see the comment I pinned to the top which explains why this common misconception is incorrect.
Actually, I have added a disconnect switch on the side of one of the battery boxes, the answer to your question is to disconnect the positive connector. Thanks for watching.
@@ImnotChuck. what kind of disconnect switch did you go with and how is it installed? Can you post a link to where you purchased it? Sorry for all the questions but I’m new at RVing. Thanks
The trailer is equipped with a "converter," which contains a battery charger. In addition, the batteries are charged from the alternator in the tow vehicle when its engine is running. Thanks for watching and commenting.
@@ImnotChuck. Think about it when charging,the way you wired it the charge voltage would hit the first battery first then to the second battery through the jumper wires,if you would have put the ground wire on the second battery the charge voltage would have been more evenly distributed charging both batteries at the same rate? just m 2 cents
My travel trailer and truck are set up to charge the house batteries from the truck, which is the quickest way to charge them. Charging from a generator is usually done by connecting the AC output from the generator to the shore power input on the RV, and then the converter on the RV charges the batteries. Solar panels should be connected to a solar charge controller, which is them connected to the house batteries to charge them. I plan to do a video on using multiple charging sources. Thanks for the question.
I'm reading your answer, I'm Not Chuck, but I am confused. Is there an AC output on all generators? The people who I bought my van from said that I should run the generator while I am driving to help charge my house batteries, but they never said anything about plugging in something! P.S. The previous owners did tell me that they just stayed in RV parks. They kind of looked at me weird-like when I mentioned my desire to boondock, and asked me WHY would I want to do THAT!! haha!! Thanks again I-N-C!!
It doesn't matter whether you connect the trailer to one or two batteries since the batteries are connected together. The difference in potential (voltage) between the two connected batteries will cause them to equalize.
I see this suggested on many articles and forum posts about parallel RV batteries. As an electrical engineer myself, I agree there is no meaningful reason to connect one cable to opposing batteries. From a purely textbook sense, those 0/1 gauge wires will have a tiny loss over the ~2 feet or so, but in practicality, it won't be noticeable.
What good does it do to put such heavy cables on the 2 battery's if the cables from the RV are so small?? You might burn the small cables up doing that>>you think??
Hi James. That's a interesting observation. The two heavy cables between the batteries ensure that the two batteries function as one battery; that's because the resistance of the heavy cables is very close to zero ohms. The system wiring in my RV is fuse protected so there is no danger of the wires getting hot. Thanks for watching.
In order to avoid draining one battery faster than the other, both batteries should be the same size and the same age. Thanks for watching and commenting. Please subscribe if you haven't already done so.
Added 8 Feb 2018. At about 4:20 in the video, I called the Interstate SRM-24 battery a "deep cycle battery." It is not a "true" deep cycle battery. I should have called it a "dual purpose battery."
There are some very interesting comments about the connection of the trailer's white ground wire to the negative post of the left battery instead of the right battery, so I will address that in some detail in this post.
First, as I have previously posted, there would be no harm in connecting the white ground wire to the negative post of the right battery. Electrically, there is no practical difference between the two connection points; here is why.
The two negative battery posts are connected by a 1 AWG cable that is 24" long; its resistance is 0.25 milliohms, which is .00025 ohms. The internal resistance of a lead acid battery (such as those used in the video) is at least 50 milliohms when the battery is new and rises to as much as 1 ohm as it ages. So, there is at least 400 times ((50 + 50)/.25) as much resistance in the two batteries as there is in the black cable.
Looking at it another way, the white wire is 12 AWG and is also about 24" long; its resistance is 3.2 milliohms, which is 12.8 times as much as the 1 AWG black cable. So, if I were to lengthen the white wire just 2 inches, I would have added more resistance with that two inches than the resistance of the entire black cable. Would that have had any practical effect on the batteries? No... just as the .00025 ohms resistance of the black cable has no practical effect.
If you have a different opinion, that's fine. We will just have to disagree. Thanks for watching the video and please subscribe to the channel. I will add a solar charging system in a future video.
Can you explain how to add a cut off switch to the batteries? Read below to see why I am interested in one. Is it simple to do?
@@YAYA-bv7po very simple. It basically goes in between the neg cable or pos cable (depending on which person you are) from your trailer. Bolt it on somewhere n ur done.
@@YAYA-bv7po It is simple to do. I mounted my cutoff switch in the positive lead on the side of one of the battery boxes. That way, I can turn the power on and off the entire RV from the battery location. Thanks for watching.
@@miztrusa Thanks Mike. It's better to put the cut off switch in the positive side because the steel frame of the RV is often used for the negative side.
I watch TH-cam videos all the time. I must say it's extremely rare to find someone who speaks clearly and is precise in their instructions. This video made me enjoy your experience immensely. Thank you for the time in making this video.
That's a very nice compliment. This was actually my very first video.
This was a great video demonstration for a complete novice like myself. I really appreciate his slow and methodical demonstration that was so very helpful to me and I'm sure many others. Thank you sir!!!
Thanks for the kind words and for watching. I wish you good travels.
hello from the rainy warm ozarks im not chuck! while i was preparing my wakeboat for winter , i noticed the battery connections were secured just like yours!!! my moomba 24ft. wakeboat built in maryville,tenn. battery connections came from the factory just like yours!! i appoligize it took so long to respond, but my internet at my fithwheel rv is poor. i went up to the bathouse and laundry to download this. tight lines and grace be with you!
Thanks for sharing, Phillip. Hope to see you soon.
@@ImnotChuck. gimmie a holler when you in the area. im at branson and will be heading back to ozarks.
Wow!! Thanks, INC! Watching this video, I realize that I am missing the Positive cable from my engine battery to my house batteries!! No wonder the darn house batteries don't charge when I am driving!! I can't wait to climb under my van tomorrow to locate it!! You are PURE GENIUS! Thanks soooo much!! Happy trails to you and your wife!!
Glad you found the video helpful. Thanks for the compliment.
Great presentation, very tidy setup. One of my pet peeves is to see cluttered haphazard wiring setups. Yours was top notch and gets my 100% approval.
I try to keep things simple and to the point. Thanks for watching.
This was the perfect demo and explention I was looking for to add a second battery to my popup trailer. Thank you for making this.
That's just the result I hoped for. Thanks for watching and commenting. Please subscribe if yo haven't already.
yeah except its wrong.
Great advice to stretch out battery power! I had an old Tioga with a mish-mosh of batteries and because they didn't match up too well the whole bank drained out pretty fast. Trying to get your battery specs to match up will help even out charging and discharging. Thanks for posting this up.
Thanks for watching and for your comment. I learned this lesson the hard way. Please subscribe if you haven't already.
Just make sure to attach the positive trailer wire to one battery and the negative trailer wire to the other battery.
Great video, I would consider placing the negative connection to the trailer on the negative of battery #2 so that the load comes out proportionally even preventing discharging one battery then going to the next one.
Thanks for the compliment and for your suggestion. I will look into it.
Charles in Charge...Food for thought. Your typical true deep cycle (not dual purpose) 6v golf cart battery has 225ah, whereas your typical 12v dual purpose deep cycle that many people use has around 75ah. Tip: you only have 50% of that usable charge, or 37.5ah. If you draw it down more than that, it will damage the battery and severely shorten its lifespan. Two 12v in parallel will stay 12v but have 150ah, or 75ah of usable charge. Two 6v with 225ah hooked in series will become 12v but stay at 225ah, or 112.5ah of usable charge. If you build a battery bank of four 6v 225ah two pairs in parallel (6v 450ah) and then series the two together it will be 12v 450ah with 225ah of usable charge.
In principle, I agree with your analysis, although even deep cycle batteries should not be discharged below 12.5 volts. Thanks for watching and for the "food for thought."
Great tips and your instructions were very helpful. Thank you!
I am glad to help. Thank you for watching, commenting, and subscribing!
Love your videos! Can't wait for a new one! You make me feel that I could do this myself!!
I am satisfied that you could. Thanks for your support and for subscribing.
I found you through Barb!
I hope you enjoyed your Video she made for you! 😁
Thanks for the lesson! 👍👍
Welcome to the channel and thanks for your comment. Barb is a very talented cook and loves to laugh. We both had a chuckle over the dehydrated water.
I've not read all the comments and maybe you've changed from a year ago, but so that you get better flow thru the batteries and prevent a dead cell you might have put one or the other connections on the other battery, This way your flowing from both directions thru the entire battery bank. This is a new style of connection that most everyone is changing over to now.
Thanks for watching and commenting. Please see my pinned comment at the top of the list. You are certainly correct that many people are doing as you suggest. If you haven't subscribed, please do so.
Awesome show, you sound like a trained educator
That's a really nice compliment; thanks for that and for subscribing.
Finally I found a good spot like your hookup for batteries...
Thank you...
You are welcome. Thanks for watching.
Hi Chuck your right am thanks for a fast reply I did what you said used three this way heavy cables like you say it works really well thanks for sharing your knowledge
Good info. Size of stud, nuts, wire etc. Very good info.
Thanks. I try to focus on the facts.
Great video! Superlative step-by-step explanation.
That's a very nice compliment. Thanks for that and for being a subscriber.
Very helpful! Most other TH-cam tutorials are a bit vague and confusing. I know what to do now! Thanks!
You are welcome and I wish you success with your project.
Thank you! I just found your channel because we are getting two batteries today to replace our one old battery in our 5th wheel. Your video is very well made. I saw you have some Bible videos so I subscribed.
Thanks so much for watching, commenting, and subscribing. The Bible videos come out each Saturday at 6 am central time. Glad to have you here.
I just added two batteries to my van, I'm trying to upgrade my system. Love informative channels. This is how we all learn. Thanks for the video.
Thanks for the comment and I hope the video helped you in some way.
Great video - Very detailed - Thank you for posting
Hello Gabriel. Thanks for watching and for the kind words.
AMAZING video! Quick, clear and concise. Love videos like this! Thanks I'm Not Chuck!
What a great compliment. Thanks for that and for watching.
Here's a nice simple to understand video about getting more available power in your travel trailer. Thanks I'm not Chuck. I appreciate this.
And I appreciate you watching and complimenting, Dan.
I have dual batteries in my truck and in the camper..and I installed a 6000w inverter to only run refrigerator while travel and turn my LP off now then throw a transfer switch to switch it back to site power, very happy with this install..
Wow, 6kw inverter is big. Glad it's working for you. Thanks for watching.
Nice work, Not Chuck! Thanks for a clear, easy-to-follow procedure video!
I am glad you found the video helpful. It have more views than all my others combined. Thanks for watching and for the positive reinforcement.
Looking for buy BATTERY in USA ! Found a really good deal on these Batteries at www.bigbattery.com/deals. Use the discount code { Lithium5 } to save an additional 5% discount.
Enjoy your videos. Keep up the good work!
Thanks for the compliment and for watching.
I used your video to do the same. Good video. Thank you.
Thanks so much for the compliment.
Thank you. Enjoyed the video. Easy to follow. I had a sailboat with two deep cycle batteries. They would charge from shore power when connected or from the alternator when under power. Very similar to my camper? Charging while plugged in, and charging through the truck alternator while travelling. On the boat I had a battery isolator. I was told it was very important to balance the charging of the two batteries. Would this apply to two batteries on a trailer? I’m trying to expand my off grid camping power and am doing my research.
Well done, nice and simple. Like 2 water butts connected, drain water from the tap end one will drain both at the same time. not just the tap end water butt.
Thanks for the compliment. Please subscribe if you haven't already.
I had the 2 batt setup on my RV for years. I always had one batt wear out before the other. A mechanic i know that works at Lockheed Martin told me to run the RV wires one from each batt instead of both from one and I never had another issue with 1 batt going bad before the other.
Thanks for your input and for watching. I have switched to two six volt Trojans in series.
@@ImnotChuck. what is the benefit of 2 six volt batteries vs what you had? I am in the process of getting batteries for my travel trailer and I am having a heck of a time deciding which way to go! I am NOT a mechanic, nor do I have much experience with electrical. I feel like most people making these videos are speaking far to technically. you seem to explain everything very easily.
@@paullywalnutz Thanks Paul. Assuming equivalent size batteries, putting in two batteries instead of one doubles the amount of power storage you have available. That is true whether you put in two 12 volt batteries in parallel or two 6 volt batteries in series. Good deep cycle batteries are more readily available in 6 volt versions (largely because of the electric golf cart market.) For that reason, I am now running two Trojan T-105 6 volt batteries in series. Of course, since I made this video, lithium iron phospate batteries have come on the scene, and are the best choice if you can pay the price. When my currect batteries are exhausted, I will probably go to LiFePO4.
@@ImnotChuck. THEN YOU WILL HAVE TOO BUY A POWER CENTER CAPABLE OF CHARGING LITHIUM AND A DC TO DC CHARGER FROM YOUR ALTERNATOR TO THE CENTER. NOT FOR ME.
Great video! Thanks for posting.
Glad you enjoyed it! Thanks.
Hi Chuck thank you somuch you were correct I just did what you said to 3 batteries it works way better with grunty cables
Great job on the video, you made it simple and easy to fully understand. However, I would suggest an add-on to the video and that's to be carful with wearing a watch, especially one with a metal band and/or a metal clasp. I had an incident where my watch touched the positive lead casing a burn to jump to the opposite side of my wrist. Apparently the current went right though my wrist. Believe me a 12v battery can really give you a jolt.
It would be better to remove any metal from your hands. The problem is not so much shock as it is burns. Thanks for watching and commenting. Please subscribe if you haven't already.
Hi Peter. Thanks for watching and for your question. For the answer, please read my comment pinned to the top. The short answer is that it doesn't matter as long as large diameter cables are used to connect the two batteries in parallel.
Great video Chuck!!!
Thanks Jack. Hope things are well with you.
Nice video not Chuck very informative and kept things simple. One tip though, if you connect the trailer wires to different batteries (positive to battery 1 and negative to battery 2) you will get longer life out of your batteries. Wiring both to one battery the trailer will draw off that battery first weakening it over time. Batteries in parallel are only as strong as the weakest battery. Hope this makes sense.
What length jumper cable would you recommend . 1ft or 2ft?
I understand that most people have been taught as you describe. However, I don't believe that it matters at all. See my comment pinned to the top for my reasoning. Thanks for watching.
thanks for making this video, it was very helpful
Thanks to you for watching, commenting, and, most of all, subscribing.
I wish I had a dad like you to teach me everything
What a great compliment. Thanks so much for saying that and for watching.
Thank You! Enjoy your Videos 😁
My pleasure. Thanks for watching.
I added a disconnect switch to my battery box to cut power instead of unhooking the cable. Works slick
Excellent idea. I did the same on my most recent RV. Thanks for posting.
The battery store I use recommends this, Hook the positive cable from the trailer to one battery and the negative cable from the trailer to the other. This ensures you get equal drawdown from each battery.
Hello, and thanks for watching and posting. Please read my pinned post for a technical explanation of why I don't believe that is necessary. It doesn't matter which way they are connected.
@@ImnotChuck. Not in anyway saying you are wrong in the way you connect. As a matter of fact, they also recommend when you replace one battery, you should change both with two new units. I went this route on my IPod and have never had an issue
@Jack Smith I would be changing battery stores if I were you, it is complete nonsense to suggest the only way to get equal drawdown is by attaching the pos to one battery and neg to the other. Equal drawdown is attained EITHER that way or using both terminals on one battery when they’re connected in parallel.
@@steviebee1989 you need to learn how to completely read a statement. Then think it through. No where did i say this was the only way. I was SIMPLY stating that this is another option. Which, by the way is supported by others posting to TH-cam and some Rv retailers.
@@steviebee1989 You are Absolutely Incorrect 💯%!!
They will not draw down equal. They will eventually equalize after you turn off the draw. And the primary has to overcharge to push power to the secondary battery.
I managed an Interstate Batteries for 2 years and was an assistant manager for Batteries plus ➕ for 3 years 👍
Might want to connect positive on one battery and negative on the other battery. This will drain both battery at the same time...
Thanks for watching. Please see my pinned comment at the top.
Outstanding video, thanks for sharing.
Hi Scott. Thanks to you for watching and commenting.
Hello, very informative video as well as the detail of your pinned comment. Thank you. My trailer is about a year old and I am looking to upgrade my cables as I do have a problem with one battery discharging faster than the other. I’m guessing it is because the dealer only used 8 ga wire to connect the two together. I even switched the batteries and the way it’s wired it still discharged the one with the main coach cables first. Can you give a suggestion on running new cables to the fuse panel? Currently it’s not marked but looks to be 8ga maybe 6ga at the most. Is there any disadvantage to going too big, or a point that there is no addition benefit to a thicker ga? Thank you.
8 gauge wire is sufficient from the batteries to the fuse panel and is actually better than the 10 found in most travel trailers. My suggestion for very heavy cables is only to connect batteries in parallel. It could be that one of your batteries is just weaker than the other, and there isn't anything I know to fix that. Thanks for watching and for commenting.
thanks for the vid, just got both my batteries stolen on a trailer that i just got, so did not know how to hook a pair of new ones up.
You are welcome. Thanks for watching and for commenting.
Excellent video - thank you!
Thanks for the comment and for watching. Safe travels.
I got rid of my single 12 volt battery and bought two 6 volt batteries, ran them in series and now have 12volt with about an extra 185 amp hours more than two twelves ran parallel like you did.
Using two six-volt batteries in series is preferred by many people, and is a good method. However, the specific amp hour capacity in either case depends upon the batteries chosen. Thanks for your comment; please subscribe if you haven't already done so.
Thank you I followed your steps and I happen to have the same Interstate Deep Cycle battery
Excellent Ron. Good luck with the batteries; take care of them and they will provide good service.
I am preparing to upgrade my RV to two house batteries. Instead of using two Interstate (not true deep cycles) 12volts in parallel, I'll be using 2 T105 Trojans 6 volts in series. My personal research has led me to the conclusion that because Trojan makes only deep cycle batteries and is the gold standard for the entire golf cart industry, and is almost the same cost as Interstate, is a far better buy. 2 6v Trojan T105s will give me 100ah at 12v. I will be adding 2 more in a couple of months when I install my solar system. That will put me at 200ah at 12v. For now, I am using a Predator 3500 Generator/Inverter when boondocking.
John K, You have obviously done some research about batteries, and I like your plan. I don't have any personal experience with the T105, but I know that Trojan makes fine products, and the specs on the T105 look good. I especially like that you have chosen a flooded lead-acid battery; I will go into some detail about that in the next video. Thanks for your comment; please subscribe if you haven't already done so.
John K ,hey,the two t-105s @12volts are 225AH. I've been using them for 10 yrs
yes Jack is correct. The 2 t-105s will give you 225AH not 100AH.
Good video, thank you. However, I have to agree, the negative wire from the trailer should have been connected to the negative post of battery number two. It would help both batteries to receive equal use and therefore wear equally.
Thanks for watching the video and taking the time to comment on it. I also appreciate the compliment.
Great explanation, really clear!
Thank you very much for the compliment and for watching.
Very well done video. Thanks.
Thanks for watching and for the compliment.
Did you have to modify the battery boxes at all to make them fit? Looks like you may have cut off the battery box handle on the right side box.
No, I didn't modify the battery boxes, but the boxes are different brands, and slightly different configurations. Thanks for the question and for watching.
Great video, not-Chuck! Thanks!
Thanks. I am glad you liked it; please subscribe if you haven't already done so.
Great video. I have a 1 year old battery. Can I add another battery parallel even though it’s 1 year old? Would 4 gauge cable be ok? What size cable do you recommend? Thanks
Larger diameter cables are better, but four gauge will certainly work. And generally, it's better for batteries in parallel to be "mates" in terms of age, etc., it's acceptable for them not to be. Thanks for the nice words and for watching.
Quick question, when you want to charge the batteries with an charger, how do you connect the leads, just to the pos and neg to one battery or pos on Batt A and Neg on Batt B?
Good question. The answer is to connect the positive lead from the charger to either of the positive battery terminals, and the negative lead from the charger to either of the negative battery terminals. Because the batteries are in parallel, it's easy. Thanks for watching.
Hi, when adding a second battery, does it need to be the exact same brand or specs. I have a second 12v deep cycle battery but it's from Costco and the one in our rv is an Interstate 12v deep cycle. Thank you very much.
Yes, both batteries should be the same age, brand, and specifications for optimum performance and life. Otherwise the newer or stronger battery will do more work and age faster. Thanks for watching.
Make sure both batteries have the same date codes so that there is little difference in the capacity of both batteries. If one battery is older than the other, it may have a lower voltage/current capacity causing the two batteries to "fight" against each other, and may cause early failure of both. I found this out when I paralleled two batteries in my Jeep, one original, and another 4 months older. Try to pick both batteries off the shelf with the same, latest date codes. Look in the back of the shelf for the newer batteries, as the seller rotates the older batteries towards the front so they get sold before they get too old. ALWAYS keep both batteries shiny clean, because road dust has iron rust powder (from rusty cars and trucks) in it causing a high resistance path between the positive and negative posts, draining the batteries even while not being used. I use Vaseline to coat the posts to keep corrosion from starting.
Very thoughtful ideas. Thanks much for the input and for watching. If you haven't subscribed, please do.
They have a special grease for batt. Terminals I tk.
Nice video, thanks for explaining everything so clearly. I'll actually be able to do this. We take long trips through the desert and next time would actually like to keep the refrigerator running. Can I apply this same technique if I want 3 aux batteries? is it safe to have 3?
Thanks for the positive comment Michael G. Adding a second battery will effectively double the time you can boondock. And a third battery is completely safe and done in exactly the same way. I have another video planned that shows how to add a couple of solar panels to the system; solar panels are great in the desert.
What length did you use for the 1 gauge jumper cable 2ft?
I have sold that trailer and gotten a different one, and I honestly don't remember the length of the cable. Two feet sounds about right. Thanks.
Hi, as many others have said, there is a problem with connecting the output cables ( and input cables, for that matter ) to one of the two batteries. You are right that the resistance between the batteries is negligible but if you see what the battery manufacturers say, it is always to connect from the positive of one battery and the negative of the other, with both batteries connected in parallel as you have. The reason, I believe , is the drop in internal resistance as a lead/acid battery discharges, making one battery work harder than the other, so to speak. It seems intuitively correct the way you have done it, but the manufacturers say differently.
It's not a matter of intuition; it's physics. The manufacturers who recommend differently do so because they don't want to bother explaining the science involved, so they take the easy way out. As I have said, there is nothing wrong with connecting parallel batteries with one connection at the positive of one battery and the other at the negative of the other battery, but there is nothing to be gained by it, if heavy gauge cables are used between the two batteries.
You are only considering the physics external to the two batteries, they are not a perfect electrical supply but a collection of chemical elements which act together to produce electricity. In a perfect system, you would be right as both batteries are effectively connected to the same inputs and outputs but in practice it's very different. I only teach physics up to students of 16 years , higher than that I am only a biologist, so I rely on the experts on this. All the manufacturers in the USA, Europe and Australia give the same advice about connecting across the batteries, as do the suppliers of chargers and inverters. If you're not a heavy user of batteries then it won't make much difference but in heavy use it will make a real difference to the working life of the set up.
As a life long engineer I must agree with Crusty. A U.S. Battery representative explained using a terminal from each battery as outputs enables greater equalization on draw down and recharge. There is, as proved by certified testing an increase in the loss of power using the terminals from only one battery in a 2 battery set. Basically, over the life of the battery under normal circumstances, connecting them as shown in your video reduces the life of the output battery versus the second battery. It's measurable over the life of the battery. There are other reasons why every single battery manufacturer recommends using one terminal from each battery as outputs.
Thx Crusty...I have watch several of these videos and am amazed how many connect the house connections to the SAME battery instead of using the other battery. Seems about 50% are doing this. Yes, it seems it would not matter but i think i will stick to using the positive of one battery and the negative of the OTHER battery just to be safe. Then i will be Will Prowse approved, lol!!.
Thanks "not Chuck" You make it look easy.
I thank you for watching and for the nice compliment. There is lots to know about an RV, and most of it is easy to learn...after you have done it once or twice.
Chuck, you are using 1 gauge wire for the "Jumper", is that the requirement? I have been told that as long as the Jumper is a heaver gauge than the wires coming from the Trailer, that is fine, what say you?
Larger is better because I want to avoid ANY significant voltage loss between the two batteries, and thus essentially make the two batteries perform as one. That will eliminate one battery discharging a different rate from the other. In addition, some trailer manufacturers use smaller wire than they should to go from the battery to the converter, which makes the problem even worse. Please read my post pinned to the top of the comments for more info. Thanks for watching and for commenting. Please subscribe if you haven't already done so.
What size are the ends of the cables that you used? Great video thank you!
The holes in the connectors are 5/16", but yours should be sized to the studs on your batteries. Thanks for watching.
nice vid.. unfortunately you took out a worthless battery, and replaced it will another worthless battery.. (not deep cycle) get a couple of t-105s or so. I found the GC2 size (golfcart size) battery box like you use at Walmart online. You can get a good 6v GC battery at Costco for $93 dollars each, and have a true deep cycle system.
you use a nice size cable between the batteries and use the same too small cable to RV.. that's where you need the size more than between batteries.. and it does matter a bit on where you connect the leads,, one to left bat positive and other to right bat negative to keep the pull the same between batteries..
keep up the good work.
Thanks for the compliment and for your opinions. I agree that Trojan batteries are quite good. Please subscribe if you haven't already.
Carl Newton j
Thanks for watching and for your input. As to the relative worth of dual purpose batteries versus true deep cycle batteries, I agree that true deep cycle batteries are better, but I am not sure whether they are sufficiently better to justify the price increase. I am now testing some cheap dual purpose batteries to see how they perform with proper maintenance and correct charge and discharge patterns. So far, they are doing well, but I am only eight months into the test. I will be doing a video on that experiment in the future. Please subscribe if you haven't already.
Is the heavy cables between the two batteries necessary? The feed wire for the trailer seems much smaller, so couldn't you size the wires between the two batteries to the same size as the trailer feed wires?
Hi. Thanks for watching. It does seem like smaller wires would be okay, but the purpose of the large wire between the two batteries is to keep the batteries equalized. If not, then the weaker battery will discharge faster and fail much sooner.
There is Absolutely no requirement for the heavy cables. Even with a everything on in the trailer you would never draw enough amps to need it.
And the Proper way to hookup the trailer wires to the batteries is Positive to one battery and Negative to the other.
That way the batteries will Charge and Discharge as a pair. The way you have it by only hooking up to the one leaves the batteries to feed off each other.
And if you are looking for longer run time and Amp Hours your better off with 2 6volts. Golf cart batteries are the same footprint as the group 24 just 11/2 inches taller.
@@jamesglenn520 If you would read the scientific explanation that I wrote and pinned to the top of the comments, you would have the facts, and the correct answer to both your comments. The short, heavy cables connecting the two batteries eliminate any significant difference in the resistance due to the connection position of the cables. Your post is just one of many repeats of an old wive's tale told by shade tree mechanics with no basis in science. Thanks for watching and for posting.
@@ImnotChuck. atta boy Chuck
Chuck, am old school, love marine deep cycle..Have 4 105ah…These are at home for emergency
Only..they serve me well…But for rv, etc, where your constantly taking them down to low limit,
Even past 50%, which I have when I had an rv years ago with young kids, gets cold at night
Was forced to run past 50%…they were luck to last a season…You should really think about
Going with lithium..long run it will pay..
Thanks for the vid..
Dennis
Hi Dennis, and thanks for watching and commenting. Of course you are right, and I am thinking about LiFePO4. I am a ham radio operator and am planning on putting my HF rig in the trailer for our next trip; it will be a big drain on the deep cycle Trojans FLA's that I have now. But $2 grand is a lot to spend for two batteries. :-)
I have a ground wire from the camper along with the positive and negative wires (3 total). Where would you connect the ground?
The ground wire from the frame of the trailer should be connected to the negative post of either battery. Thanks for watching.
If your trailer was built with just one battery, wouldn't the charging system charge at a single battery rate (??). If you add a second battery, should the recharge rate be changed?? I have a single battery on my trailer and when it's plugged into shore power, I believe the charging rate to the battery is just over 13 volts. Would that charging rate we okay for "two" batteries?? Thank you :)
Good questions! The voltage of two 12V batteries in parallel does not change, so the charging voltage does not change either. In addition, the charging current (measured in amperes) is regulated by the batteries; they will take only as much as they need (up to the maximum that the charger can supply.) However, it will take twice as long to recharge two "hungry" batteries as it does to recharge only one. Thanks for watching and for the thoughtful questions.
Great instruction!
How long are the 1awg cables you used? Thanks
Nice work, thank you
I appreciate the compliment. Good luck.
I have the same batteries. I have 2 hooked up now. Thinking about adding 2 more rv batteries. 4 altogether
Hi, and thanks for watching and posting. Before you buy more batteries like the ones in the video, consider going to a true deep cycle battery like the Trojan T-105.
Hiya, reading the voltage on a battery is no indication of the state of the battery you have to use a load test which is a dummy load and a meter that indicates the state of the ability to take and hold charge. Here in the U.K. most garages will have a tester and will do it for free. Don't be to surprised by the hefty spark when doing the test, this is normal. Batteries are not cheap and disposing of a healthy one when you don't need to is expensive. If they are not sealed cell units make sure the distilled water is topped off to the correct level before testing as a faulty cell may boil. You don't need to earth the second battery as this will form an earth loop, which in extreme cases may be a problem, one negative connection is sufficient as is one positive lead. Happy camping...
Thanks for watching and for commenting. Testing a battery under load is common here in the US, however load testers are less accurate than measuring the voltage with no load and checking the specific gravity. In fact, load testers are seldom adjusted to the size of the battery under test and can overload batteries during a test and permanently damage them. I have a battery load tester that I designed and built, but seldom have any reason to use it. When you have time, watch my two videos on specific gravity testing. As you will note, it is not a good idea to add water to a battery just before checking the specific gravity because the water will not be properly mixed in the electrolyte and the readings will be incorrect. Topping off cells with water after testing is proper. As to your comment about "earthing," electrical systems in RVs are never connected to earth ground except when using "shore power." I am sorry my reply isn't more positive, but I have studied lead-acid batteries extensively and formed my own opinions. Thanks for yours.
Good video can i hook up both batteries like this for my boat 12 volt trolling motor, and how do I charge the batteries when there hooked up parallel like this
Yes, trolling motor batteries work the same way, and are charged just as if there was only one battery... just connect the charger positive anywhere on the batteries' positive, and negative to negative. Thanks for watching and posting.
Hey, I'm Not Chuck, gotta another question for ya.
For my TT I have two 206 ah SOK batteries. Can I wire them in series?
I was not familiar with that battery, so I googled it. It seems to be a 12V LiFePO4 battery, so if that is correct, there is no reason you can't wire them in series. Of course a series connection will result in the voltage being doubled to 24 Volts which means that all the DC equipment in your travel trailer will need to be 24V devices, which doesn't sound right to me. If you have 12V devices, you will need to wire the batteries in parallel in order to keep the nominal voltage at 12 Volts. Thanks for watching.
@@ImnotChuck. Thanks I'm Not Chuck, I googled 24 volt converter chargers and I think they bring the voltage back down to 12 volts when the batteries are connected in series. Does this sound right to you?
I want to build a powerful 24 volt system, I've been watching Will Prowse speak about 24 volt systems. TKS for your honest opinions.
I noticed you wisely used a ratchet wrench with a short handle. Smart. that way y0u reduce the chance of accidentally "bridging" the terminals and zapping yourself.
Thanks for watching and commenting. I find lots of uses for that little ratchet; the handle is hinged to the head for times when there is very little room available. The only problem is that it doesn't provide much leverage.
Keep a piece of pipe handy to slip over your short handle when you need more leverage. Great post.
Can't go wrong with an Interstate Battery! Last fall I had my camper plugged into the house, while I was doing some cleaning and getting it prepared for winter and forgot about it and thought nothing of it. My battery was 4 years old. Well ....3 or 4 days later it exploded! I called Interstate Corperate to find out why? They told me that it keeps charging when you are plugged in, and here I thought it only charged when going down the road being towed. Well guess what? Interstate brought me out a brand new battery! I didn't even ask for them to replace it, I was just wondering how to prevent another battery from exploding in the future! Customer service like THAT is why I will always buy Interstate from now on!
It's always great when good companies stand behind their products. Thanks for subscribing, watching, and commenting.
The Ac/Dc converter of your trailer should have cut back or cycled the charging off when you were plugged into the house. The battery may have exploded to an overcharging failure of the converter.
hughie voso Probably correct.
Ive found that a lot of devices I have in my home, such as my cable internet modem, the wifi router, and the cell-spot router for T-Mobile, all are connected to the 110AC, and each one converts it with the big plug that goes into the wall, (Switching power supply AC>DC0 all run 12v at the device itself. I purchased a Marine battery, deep cycle, a cheap 12v solar panel for RV's, and have hooked each one up, by cutting the plug off of them, and connecting them directly to the 12v batter. I did it this way, because if I purchased an Inverter, and plugged the devices directly into the inverter, I would be then converting DC from the solar panel, to AC in the inverrter, which then would be converted back into DC with the plug. This makes it roughly 60% more efficient after I did the math.
That's a good way to make more efficient use of DC from solar panels or from any DC source. Thanks for watching and for commenting.
This went so far over my head.
@@Simply_Anthony83 Thanks for watching and commenting. If you don't "get it" you should probably not work on the electrical part of an RV.
Thanks, good job!
You're welcome. Thanks for watching, commenting, and subscribing.
This is how i planned on doing this, my question is. Do you need identical batteries? I.E. say one is a group 24 with 500cc and 600c and the other say a 27 or still a 24 group with 600cc and 750c. Reason i am asking is i will be converting over to interstate RV batteries but currently, i have an Oreily deep cycle that has been good but i want to upgrade. However, this battery is still in good shape no sense in tossing it. once it dies ill get another interstate identical to it.
Both batteries should be identical in both size and age, if possible. Otherwise, they will discharge at different rates, and the capacity difference will increase over time. Before you buy Interstates, I would suggest you consider true deep cycle batteries such as the ones made by Trojan.
Interstate Batteries are imported now and Trojans are also.
So the quality is not what it was years ago. If you have a Batteries ➕ bulbs in your area the DURACELLS are the best 🇺🇸 made available.
*thanks very helpful going to do this today I have to Lithium batteries*
Hi, and thanks for posting. Good luck with the new batteries.
Battery that are connected in parallel. It's better to connect positive cable on one battery and negative cable on the other. Then you drain both battery equally.
Be sure to have same length on both cables between the batteries.
Just a tips.
Thanks for watching and commenting on the video. Please read my my post pinned at the top for an explanation of why I do not accept that there is any reason to wire my batteries differently from what I showed in the video.
Hi if you hook them in Parallel will that give you 24 volts or still 12 volts
@@Farmer2492 What you see on the video is a parallel configuration. If you were to hook the two 12V batteries in series, then you would have 24V. Thanks for watching.
I'm not Chuck, I have another question. I have enough room on my trailer tongue for three batteries, can I connect three batteries in parallel for more electrical storage?
Sure, just be sure to use heavy wire and good connectors. It's preferable to have all the batteries be the same type, size, and age.
@@ImnotChuck. Thanks, I'm not Chuck, just bought a bumper pull, I'm taking a boon docking zig-zag route, (six weeks travel) to the coast of Oregon, from Weatherford Texas and need all the juice I can store, (powered by a Champion Gen).
I'm subscribing to your channel now.
Good luck.
@@nehpetsrellek2750 Sounds like a great trip. From what I can tell, the Champion gens are good units. Take care.
@@ImnotChuck. 👍
I put a 80w solar panel and cheap mppt controller on our one 110a battery - max charge is about 5 amps - the beauty of this approach is that the battery seldom falls below 1/3 empty so it should last 5 or more years - if we were doing it again we would use the new thin solar flexible panels that just stick to the roof
Keeping your battery at 66% charged or higher is good for its life expectancy. In an upcoming video, I will present some graphs that show that 80% pays even more dividends. A lot of people don't realize that a 12V battery that is down to 10.5V is considered completely discharged. Thanks for your comment. I hope you also subscribed.
We used this www.ebay.co.uk/itm/5A-10A-12V-24V-MPPT-Solar-Panel-Regulator-Charge-Controller-55V-Input-DC-USBBR/292425975504?hash=item4415f246d0:m:ml_V81nPz1Cjm87V-I67Jng
It float charges at 13.8volts & wiring is 12gauge silicon insulated used for RC - its been on 2 years now and has been completely trouble free - The USB ports get a lot of use charging peoples phones especially at music festivals!
Make sure you have a pint of beer charge for each cell charge.
I want to add a battery to my pop up but don't know how. First of all what color are the wires that go from the converter to the battery.
I don't have any direct experience with a pop-up and wire colors vary from one RV to another. It should be in the manual that came with your trailer, but if you don't have a manual, look at the manufacturer's web site and you should be able to find one there. Sorry I can't help more, but I would be guessing, and that's a bad idea. Thanks for watching and please subscribe.
Nice video only think as far as I know you should have put the ground from the RV on the other battery . It will work but will drain the power more from the left battery .
Thanks for watching and for the comment. Please see the post I have pinned to the top.
As Already mentioned, the ground must be connected to the battery that you are not taking the live feed from, this will ensure you get equal discharge of both batteries.
Thanks for watching and commenting. I have addressed this issue many times; please see the comment I pinned to the top which explains why this common misconception is incorrect.
When you’re not using your camper, which cable(s) do you disconnect to stop phantom drain over time?
Actually, I have added a disconnect switch on the side of one of the battery boxes, the answer to your question is to disconnect the positive connector. Thanks for watching.
@@ImnotChuck. what kind of disconnect switch did you go with and how is it installed? Can you post a link to where you purchased it? Sorry for all the questions but I’m new at RVing. Thanks
@@Sniperfox1 www.amazon.com/Disconnect-Vehicles-Waterproof-Isolator-Position/dp/B07HT19T5V/ref=asc_df_B07HT19T5V/?tag=hyprod-20&linkCode=df0&hvadid=316725397836&hvpos=&hvnetw=g&hvrand=275693295050598946&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9013601&hvtargid=pla-587054685735&psc=1
@@Sniperfox1 I installed it on the side of one of the battery boxes. Thanks for asking.
Nice video. Question how do you charge the batteries?
The trailer is equipped with a "converter," which contains a battery charger. In addition, the batteries are charged from the alternator in the tow vehicle when its engine is running. Thanks for watching and commenting.
I'm not Chuck.
Can you please give some information on that, please
Thanks
@@ImnotChuck. Think about it when charging,the way you wired it the charge voltage would hit the first battery first then to the second battery through the jumper wires,if you would have put the ground wire on the second battery the charge voltage would have been more evenly distributed charging both batteries at the same rate? just m 2 cents
Will this work on my 5th wheel that comes with 1 battery & an inverter too?
Yes, as long as the inverter is designed for a 12V input, which should be marked on it. Thanks for watching and commenting.
What difference, if any for charging with tow vehicles, or generators, or solar panels?
My travel trailer and truck are set up to charge the house batteries from the truck, which is the quickest way to charge them. Charging from a generator is usually done by connecting the AC output from the generator to the shore power input on the RV, and then the converter on the RV charges the batteries. Solar panels should be connected to a solar charge controller, which is them connected to the house batteries to charge them. I plan to do a video on using multiple charging sources. Thanks for the question.
I'm not Chuck. Thanks for your response and I love what you are doing... Keep up the great work.
I'm reading your answer, I'm Not Chuck, but I am confused. Is there an AC output on all generators? The people who I bought my van from said that I should run the generator while I am driving to help charge my house batteries, but they never said anything about plugging in something! P.S. The previous owners did tell me that they just stayed in RV parks. They kind of looked at me weird-like when I mentioned my desire to boondock, and asked me WHY would I want to do THAT!! haha!! Thanks again I-N-C!!
Everywhere I read says neg on one and positive on the opposite battery. What makes it the same in your video?
Please read my full explanation at the comment pinned at the top. Thanks for watching and for commenting.
It doesn't matter whether you connect the trailer to one or two batteries since the batteries are connected together. The difference in potential (voltage) between the two connected batteries will cause them to equalize.
Thanks chuck!
You are very welcome, and thanks to you for watching and commenting. Please subscribe if you haven't already done so.
Would there be any advantage to connecting the GROUND cable to the OPPOSITE battery ?
No, not any meaningful advantage. Thanks for watching and for commenting.
yes it will make a more even draw off the batteries more balanced..
@@cruzinbenny3750 No, it won't. That's one of those things that seem logical, but has no basis in science. Thanks for watching.
I see this suggested on many articles and forum posts about parallel RV batteries. As an electrical engineer myself, I agree there is no meaningful reason to connect one cable to opposing batteries. From a purely textbook sense, those 0/1 gauge wires will have a tiny loss over the ~2 feet or so, but in practicality, it won't be noticeable.
Can you trickle charge while you are driving with out your generator overheating ?
Yes, I use the alternator in my truck to charge the batteries in the RV. Thanks.
What good does it do to put such heavy cables on the 2 battery's if the cables from the RV are so small?? You might burn the small cables up doing that>>you think??
Hi James. That's a interesting observation. The two heavy cables between the batteries ensure that the two batteries function as one battery; that's because the resistance of the heavy cables is very close to zero ohms. The system wiring in my RV is fuse protected so there is no danger of the wires getting hot. Thanks for watching.
Do the battery's both have to be the same size ?
In order to avoid draining one battery faster than the other, both batteries should be the same size and the same age. Thanks for watching and commenting. Please subscribe if you haven't already done so.