Dude, you are tied with Dave Poz, Tin Hat Ranch, and Will Prose for the best info/teaching in solar. Each of you excel over the others in your specific areas. This is meant as a complement. I prefer your speed and detail of info and diagrams are fantastic! I learned more detail and had holes in areas I thought I knew filled in after watching your videos!
Wow, you clearly put a LOT of time into this (script, diagrams, filming, editing, etc.)! This is the best video on explaining the pros / cons and how-to on combining mismatched cells / panels. THANKS!!!
In the last example why not wire 3 panels in series ( 51V &11.76A) and then wire the other four in series also (68V & 11.76A)/ . now you could wire these two series array in parallel get you 51V * 23.52A =. 1200W
Please write a book, put the diagrams in your description because I can't afford another book that has everything except what I am looking for. It is a miracle, you speak English. You need to write a book. Please help us. We need to know how to wire that 110W panel we purchased a while back to the 200w panels we bought recently and, oh yeah, there's that 160W panel somewhere. What wires, what design, what connectors or whatever else will I need to get as much as possible out of what I already have. Thank you. I will shut up and subscribe now.
This video literally just helped me figure out the mathematic equation for my system. Under perfect factory testing conditions, ill be installing a 98% efficient system. I appreciate it sooo much!
The diagrams help it sink in Nate thank you, I’ll just watch this video another 3 or 10 times and get a new piece of paper and start again. I usually get professionals to do my electrical work but I want to DIY to understand what I’ve got for remote travel troubleshooting if something happens.
Your video is very good. Explainations and diagrams are spot on!!👍👍 Math is also awsome. The one problem I have is you keep calling it watt's law, the correct terminology is ohm's law. I say this with 49 years of electrical experience. I am not trying to bash your presentation because it is quite good, just putting this out there for information purposes. Keep up the great work!!
How about this since it sounds like you're pretty confident... If I link a credible source that states that watts law is Watts = Amps x Volts and Ohms Law is Voltage = Current x Resistance... you send me $100. Sound good?
You are the best at this. You actually have real life installs verse talking about "how it can be done" from inside a room. Thank you very much for this great information
Great video Nate, long time follower and I've referenced your material for my own RV solar installation. One way to work around the problem with panels of different voltages and amperages and preserve 100% power efficiency is to wire them into a 2nd charge controller. If budget is a concern and you've already spent $$ on the MPPT controller, the second controller can even be a lower cost PWM controller which will still boost overall power output.
Definitely! That would be moving into a dual array setup, which was a bit out of the scope of this video, in particular and if you wanted/needed to mix solar panel sizes in either of the arrays, they math would remain the same and would be treated as 2 totally seperate arrays. I'll be sure to add a video to my queue for when I talk about solar charge controllers to talk about dual array systems.
@@EXPLORISTlife Nate. If you have not already done so, please include a jump starter video to discuss multiple array systems. You can discuss the reasons why to add a separate array (under it's own SCC) would be considered, and method's of introducing the other array(s) into the current array. For instance, my system is still patched together kinda rigged. But I do think it is worthy to keep my starter battery (veh battery) charged by the panels while charging my solar system battery. I have thought to just provide the veh battery with it's own mini-array and a cheap PWM SCC, but haven't really prioritized that task just yet. My other concern regarding multiple arrays (under their own SCC) would be to avoid the blanket affect of shade on all panels connected to the shade affected array. You may have covered this, or Will Prowse did, where if any one part of a panel gets shaded, it, like you indicate regarding the volts/amps affects, can/will affect the entire energy in that entire array assembly. To avoid this, each panel should be given its own SCC so no one panel getting shaded can affect all the other panels if in an Array. My first guess would be, when having separate arrays with their own SCC would simply be to connect them (ALL) (+ - out wires) to a common terminal effectively turning all them into one main "in".
Not necessarily as sometimes having two separate charge controller not communicating with each other will send a fully charged reading to the second charge. This sometimes will have only one charger pushing current.
@@johnjones1812 Good point. When employing 2 charge controllers it is best to have the same model. If not able to do that the battery parameters must be the same between controllers. No need to communicate then.
@@Robert-jm1kk communication between two chargers is necessary for most efficient charging. I have seen where one charger will float charge or sleep in midday because it's reading the charging voltage from the other charge controller not the actual battery state of charge because they require battery voltage for battery status.
Hi Nate. Really appreciate your efforts to help us all DIY. I have watched all of your DIY solar videos, some of them multiple times to help me learn solar/RV electrical. I've learned a lot but I'm still not 100% confident in my decisions. I would like to have 2 arrays for my RV. One array will have 4 Renogy 100W (18.6V, 5.38A) panels run in S/P 2/2. These panels will be placed on the ground to get better angles to the sun and to help avoid shading. The other set of panels will be placed on the roof of the RV to allow us to charge while on the road (and in camp), but since placement is more challenging they may get obstructed. I was originally looking at the Renogy 200W but given the array specification differences it seems that their performance would be too low. So based on your advice I changed to using the Rich Solar 200W (37.6V, 5.32A) panels wired in parallel, which if I have done my calculations correctly should get us to 99.8% efficiency. Can you please double-check my logic on this? Thanks. Now for my "real" question - do you think I should use 2 solar charge controllers (say a Victron 100/50 and a Victron 150/60) or would we be better served using one solar charge converter (say a Victron 150/100). The price difference between the two S.C.C. approaches is negligible. Thanks for whatever advice you can provide! Jim
I came across your TH-cam site. Very good explanations on the panels and systems. You have done a very good job on the educational aspects of the web site. Using ABYC as a guide is also brilliant. I wish I had found this 5 years ago when I was exploring solar.
I am retired, used to run a fire LAB and I am now bored a lot. I set up a test rig a few years ago to verify the different types of 12V 100W panels and types of controllers. I used a 4 tube Florent ceiling light fixture for a constant light source. I put the panels on the light source and fed them through both PWM/MPPT controllers. Measured all the outputs, charging times, loads etc. after a few weeks of testing I came up with the best configuration. I charged a 950 Ah lead acid battery, then I would use a 2Kw Inverter to power up 3 100W light bulbs and drained the battery to 11V, then charged it back full. After doing this 15-20 times I was able to calculate the power generation of each panel and efficiency of the controllers. Then moved outside to do sun source testing. Lots of fun was had.
I have a 76 VW Camper. I installed the test solar system on the bus. I have a pair 100W panels in series feeding a cheap MMPT controller. I live in the Pacific NW and all the rain and clouds here are not optimum for solar. Plus the latitude of 48 Deg north means the sun angle is low. The standard 12v panel would not reach charging levels all the time. My testing showed only a couple hours a day they would produce charging voltage when in parallel. So I put the panels in series so when each panel made 7-8 Volts the sum of the voltages will start the charging cycle. Current is low 5-7 amps, but acceptable for this application and this actually works very well in this area. I have a pair of 650Ah Lead acid batteries and they stay full with the system. When the batteries are full the controller shuts off the charge and the panels go to open circuit voltage. The bus is parked most of the time and not used much.
The MPPT controller has a switched load, (like they all do) I am looking to use the excess solar panel power on a restive load after the batteries are full. Since the bus has a refrigerator that runs on Gas/DC/AC. I wired the switched output of the MPPT controller, to the Refrigerator electric heater (12V 1500W) through a diode. I have run this for a few weeks to see how the system will operate. The refrigerator stays cold and occasionally will freeze water on a bright day. This works very well to use the excess power generated so the panel does not sit around at open circuit voltage most of the time. But it's a manual operated, go push the button system. The power is way less than the 1500 watt design but just warm enough to boil the ammonia in the evaporator. I have also wired this into the cheap Chinese diesel heater, it will run on the solar panels alone after it is started and up to temp ( heater fans use 2.5-3.5 amps ) so it will operate on a bright day. It can't start on solar, since the glow plug on start draws 10 amps but after the glow plug cuts out the fan blowers work fine on solar.
Question for you....
Do you know of any MPPT controller that will automatically switch to the "external load mode" when the batteries are full. Or a way to automatically switch with a relay to off load the excess power. If the refrigerator load could be automatically switched, it would run on the solar panels when driving and the alternator is keeping the battery voltage above the MPPT cut off voltage. This is not all that important on this bus, but on larger solar systems, the excess power can be sent to the 1500W heater strip, or maybe a hot water heater element. . On larger RV's this could save the panels from the Open Circuit condition which is not good for the panels. .
Thanks for your time, great job on the solar series.
Although it is indeed possible, load dumping is not something I have experience with. Here is a forum post on the Victron discussion boards that may get you pointed in the right direction: community.victronenergy.com/questions/2089/mppt-dump-load.html Also... having the panels in 'open circuit condition' is not bad for the panels.
Thank for the video! After watching it an doing some comparisons, I realized I'd get the best watt output if I wired them all in series. Ended up with 250 watts vs previously I was getting something like 100 watts.
I am using 3 solar panels in parallel to charge a 12v car battery. This is used to power up 3-4 leds street lights on the wall. The lights used to stay on till about 4am. The solar panels are not of same size so I think the wire is not right to get the battery charged full. This video helped me to understand the wiring. I will try to correct it.
Thanks I new this but still I wired them wrong. Thanks to your great video I now get more watts out of the same panels. Brains need to be refreshed now and then.
Nate, you have one of the best DIY sites I have visited. Love your style. I get Volts /Watts / Amps / Parallel / Series. I was missing the part that the MPPT controller actually made the adjustments. Cool, got it.
The Series has been great! Think I've watched everything! Certainly picked up a lot of clue, from tools, to when to fuse on the roof. What about discussing East / West panels? (when one has no suitable house roof pointing to the equator). I understand that this could be more desirable as one can catch both the early and late sun rays. One thing you don't seem to have mentioned is that if there is shade on a string - it affects the whole strings production of power - so having a well chosen placement of a mix of Series and Parallel panels can be the wisest configuration. Lastly (back to East/West configs), if there is less sun on an area - does this affect the voltage or the amperage of the string? Oh - the hour long video with your friends RV - four panels down each side in series, why that format? I think I'd put the four at the front in series and the four at the back in series - so parking with one end in shade gives at least one good string. The Left & Right strings is primarily beneficial if in the complete open with the RV parked North/South. Perhaps have a method of switching between the two layouts?
Overall a good video to show why you should "not" mix solar panels of different wattage and voltages to a single solar charge. If you have to mix panels of different wattage and voltages place them on separate solar charges. Yes, it may be a little more expensive. But you optimize solar panel output and you will create redundancy. As mentioned in the video a solar array will always be reduced to the efficiency of its lowest rated panels. Always design for optimum production of solar panel arrays. In the end you'll be better off. Also be aware as you increase current you need to increase the wire diameter (lower AWG wire size) which adds both cost and weight. So increase voltage is better than current. And use good quality MPPT charge controller's for higher voltage but keep current low. Let the MPPT solar charger convert the voltage above ~14.6 volts to extra charge current. Finally, have a system properly reviewed by a knowledgeable solar system installer to verify everything is properly sized, from panels, wire runs, charge controller, battery bank and protective breakers. Do everything safe.
Thanks Bud, I now know why my 160 watt and 100 watt roof panels only produce 11 amps. When plugged in separately I can see 14 amps in ideal conditions. I have a Timber Ridge 24 RKS with the factory solar kit and the portable solar panel plug on the side. When I plug my Go Power 120 watt portable into the side port the two controllers fight and take turns shutting down. I finally bypassed the portable panel controller and plugged it into the third plug on the roof using only one controller and now I can see 15 amps from the 3 panels instead of the 20 amps I can get when totalling individually. I guess I will replace the 100 watt panel with a matching 160 watt panel on the roof and hope my 120 portable has the same voltage. I was wrong to assume the dealer knew what they were doing, lesson learned.
Point of contention: you said, "lowest common denominator," but that cannot be what you meant based on your math. I believe that you meant 'lowest volts (or amp) rating," because the lowest common denominator between 25 and 20 is 5 for the volts [wired in parallel] (and between 8 and 5 is 1 for the amps [wired in series]). Barring that, I am learning a lot through this video. Thanks!
Wow. I've mixed 3 200 watt panels with 4 100 in parallel. So my take away is I've lost 300 watts of power doing that. I've got some wiring to do. Awesome video an explanation of mixed panels. Thank you.
@@EXPLORISTlife wired like I described I was getting 49 amp on that controller. But I have a 50 amp an 60 amp. An 1900 watts of panel. Getting 100.6 amp combined. Wired properly I might get 160 amps. Will do a video on it.
Thanks Nate for providing this very comprehensive and understandable information. I have 48V electric riding mower which I'm setting up with solar, so that it will charge as it is running, thereby extending my range. Unfortunately, through using your online PV/mppt calculator I found out that my pv voltage has to be 5V above that of the 48V battery bank. From a lack of knowledge I assumed I could just have one 100W solar panel push wattage into the bank while driving it. Why does a trickle charging solar panel (the little ones you can buy for RV batteries running at about 10 watts) work on a 12V rv battery, since the voltage of that little panel would be way below the 12V of the rv battery. In my case I'd have to provide at least 300 watts of solar panels (there is no way I can fit that many panels on the support rack I'm building on the mower) in order to actuate the dang mppt controller. Is there any alternative way to push the single 100W into the 48V bank? I see this as a major drawback over a 12V or 24V system in some applications. There should be devices that up-converts (inversion from +- 18V PV voltage to +- 48V battery bank voltage) PV voltage to activate the charger at any time? Any suggestions would be greatly appreciated since I've already put in a lot of time into this built.
Best explanation on this topic I have run across, and exactly the information I needed to help me configure my ever growing solar system...thank you....aloha
Great video !! One small correction , it's Ohms law to calculate watts, amps or volts when two values are known. I'm helping my off grid neighbor who has an assortment of panels and this video answered all my questions. Good day.
Glad the video helped and I'm sorry for your confustion, but Watts law is: Watts = Amps x Volts as stated in the video. Ohms law is: Voltage = Current x Resistance Since we are given Watts, Volts, and Amps; we use Watts Law. We wouldn't use Ohms law as we aren't given resistance nor do we need to know resistance: Introduction to Electronics - Stanford Wiki: ccrma.stanford.edu/wiki/Introduction_to_Electronics - "Watt's Law states that: Power (in Watts) = Voltage (in Volts) x Current (in Amps) P = V I" Hope this helps!
I am learning so much from this channel, although there are some things that are still a bit fuzzy in my head. QQ. I own 3-160w EC panels (18.2v*8.8a) and 2-100w panels (17.1v*5.9a) I was looking for a way to combine them with minimal loss. I think the best possible way under this scenario would be to put them all in a parallel configuration. Combined AMPs 38.2 * Lowest Volt 17.1 = 653.22 out a 680w. Is that math correct?
Good video as usual. Could you maybe consider making videos on how to use software tools to add batteries and assign inverters as master inverter etc .
Wish you would cover the impact of partial shade on an array! If one panel of an array is shaded a bypass diode would allow current of a series array to be impacted but would reduce the voltage. Reducing the voltage impacts the performance of panels in parallel to the shaded panel, no?
Yes, using 2 controllers will solve problems like that. I do that now even with 4 identical panels using 2 panels on each controller. It was less expensive then buying 1 large controller and if one controlled die I will still be able to get half charge. It also give less trouble with partial shading.
i have 5 identical mppt controllers connected to the same battery bank and i am about to order one more to accomodate an extra 300 watt panel that i cant fit into any other array for reasons mentioned in this video
I appreciate this information... about keeping the panels the same size... and what you explained about adding in a smaller panel, it reduces the overall performance. My question is If smaller panels are at the beginning(negative end)of a series, then larger panels are added, is the math the same?
This was a great guide :) I had been pondering on similar problem when using 24v system and using 12v light bulbs and what would happen with mismatched bulbs in series to make 12v work on 24v and came to similar conclusions, had not thought about it when it comes to solar panels and it would be simlar problems... But it is logical when you think about it :)
Very helpful, thanks. How does using something like SolarEdge power optimizers change the equation? I’m assuming it could be substantial as they regulate the power between individual panels helping minimize the effects of partial shade etc. Would appreciate your thoughts. Thanks
I'd like to see an addendum to this video in which you explain the use of separate mini-controllers (I'm not sure that my terminology is correct, but I think you understand the gist of my request).
What a impressif and informatif video to get on the track, Thank you ! Question : if my understanding is right, can i connect in series 6 X 200 w Renogy panels on 10 Awg cables with a victron charge controller 170-100, and what about the Mc4 connectors good for 30 amp ? I made my calculation on 95% efficiency of the panels but as we all know i will be lower than that. Thank you!
@@EXPLORISTlife I will be watching this one again and again... I have 3 x 335 for 1,005 and I wanted to add one more over the dining room window for shade and to face South... But unless I get the same one, it looks to be tricky to add on to the three I have>..? I have 3 x 100 amp hours Lithium too
So, now that I'm somewhat confused as to what is the most efficient wiring,for mixed panels,I will be in direct contact in near future for set up help thanks
Thanks for the video Nate. Have you considered a video on how to wire the leisure battery to jump the van battery in the event that you drain it, such as when leaving the lights on? This is a topic I cannot find info on but I'm sure many would like to know.
Look for ANY video about how to jump a car battery! And I really mean any... Positive (Red) first to be connected. Followed by the negative (Black). Make sure to produce a good contact, with CLEAN poles and clamps! Start the vehicle. I always let it run for a short while... Disconnect the negative (black), and finally the positive (red). Be aware of the sequence! A detail many tend to forget! Easy way to keep it in mind! Red (positive) first and last. The rest in between. ALWAYS manipulate ONE cable at a time. AND do not hold them together (clamps) under your arm pit while connecting/disconnecting. A colleague literally lost is shirt and had some of his arm pit "fur" burned because of such small detail! LOL 😂 Cheers
But what questions do you ask to help decide this question? "Wire in parallel or serial?" Only after I answer that question can I start planning. Good vid.
Brilliant ... first clip i begin to understand. I have just bought a solar system for my camper van. 1x 20amp MPPT solar charge controller 1x 150v VOC 22.5v , VPM 18v, ISC 9.00A , Imp 8.33A 1X100v VOC 21.30v, VPM 17.8, ISC 6.07A, Imp 5.62A 2x 110ah V12 Batteries SO i am wondering because the solar are different voltages etc what is the best configuration ??? Many thanks and great work on your channel . DJ
I know this is an older video, but you do such a great job explaining I keep rewatching every time I adjust our solar system. Question: Why do all the Solar Generator forums make it sound like “mix & match” paneling is an absolute No-No? You seem to show it can be done? Is there a difference mix & match to a stand alone MPPT vs an all-in-one SoGen, such as Bluetti or EcoFlow? Thank you..
@@EXPLORISTlife Thank you for this.. I had been wondering and have 2 manufacture panels.. but are under paneled so that I don’t Mix & Match.. Good to know it’s possible and now off to do some math!
Great videos ! I noticed my charge controller which is rated at 100VDC and 40A there is also a Max input rating of power of 12VDC @520W or 24VDC@1040W. Questions. With this power rating would 20VDC be linear to calculate wattage ? With the power Max input does it matter which configuration is used considering wattage max capacity?
Nate, I have 3 different pannels that I wan to use together, here is the list; 1 - 210 W, 16.77 V, 12.48 A panel 1 - 160 W, 18.53 V, 8.66 A panel 1 - 70 W, 17.2 V, 4.07 A panel Here is what I came up with; combine the 160 and 70 in Parallel, resulting in 17.2 V, 12.73 A for 219 W Then combine the 210 to the other string in Series to net 33.97 V, 12.48 A and 422 W for 95.9%. What do you think?
freaking fantastic. i have space for 4 (maybe 6) x 270 or 300 watt panels and was thinking to add some in the extra space. this is so fruitful to know these plans. for example if i had space for 4 matched panels then added in 2 smaller extra ones but used a different controller to feed the same battery bank how would that work?
Great vid, do you know of an online or spreadsheet tool that you can quickly plug in your existing array and then play with what-if scenarios? Reason I ask I see some vendors with B grade panels for sale and I'd like to add to my SunPower system. Thanks
You, Will Prowse, and Hobotech should all get together and have an insane conversation. Thanks man.
Agreed, my favorite you tubers as well 👍
Wouldn't understand a word of it 🤣
If I could only take some wire, dirt, air and water, to create a power supply...lol, these three gentlemen could probably do it🎯😁☕
hmmm...
Here is a guy that can really teach useful information.
This is one of the best solar videos I’ve seen. Thank you!
Glad it was helpful. Cheers!
Dude, you are tied with Dave Poz, Tin Hat Ranch, and Will Prose for the best info/teaching in solar. Each of you excel over the others in your specific areas. This is meant as a complement. I prefer your speed and detail of info and diagrams are fantastic! I learned more detail and had holes in areas I thought I knew filled in after watching your videos!
I'm so glad you're continuing with this series. It helps so many people.
I just learned a lot
Thank you
Wow, you clearly put a LOT of time into this (script, diagrams, filming, editing, etc.)! This is the best video on explaining the pros / cons and how-to on combining mismatched cells / panels. THANKS!!!
Glad it was helpful!
Indeed! Your explanation is awesome! Thanks man!
@@EXPLORISTlife Yea that was great, thanks. In the last example, why can't they just wire them all in series?
@@riverzin3186 All in series would overvolt the charge controller.
@@evil17 Thanks for the advise
The last example of adding an additional panel that cuts output in half is super informative.
Glad it was helpful!
In the last example why not wire 3 panels in series ( 51V &11.76A) and then wire the other four in series also (68V & 11.76A)/ . now you could wire these two series array in parallel get you 51V * 23.52A =. 1200W
Please write a book, put the diagrams in your description because I can't afford another book that has everything except what I am looking for. It is a miracle, you speak English. You need to write a book. Please help us. We need to know how to wire that 110W panel we purchased a while back to the 200w panels we bought recently and, oh yeah, there's that 160W panel somewhere. What wires, what design, what connectors or whatever else will I need to get as much as possible out of what I already have. Thank you. I will shut up and subscribe now.
I appreciate the repetition of the formulas and the sums. I learn faster that way. Thank you, sir!
What? You just save me from spending unnecessary different size of panel that was not gonna work for my solar array. Thank you. 👍🏼
This video literally just helped me figure out the mathematic equation for my system. Under perfect factory testing conditions, ill be installing a 98% efficient system. I appreciate it sooo much!
Legend mate. That has simplified everything. I was worried I would lose watts on my mismatched panels. Now I know correct wiring
The diagrams help it sink in Nate thank you, I’ll just watch this video another 3 or 10 times and get a new piece of paper and start again. I usually get professionals to do my electrical work but I want to DIY to understand what I’ve got for remote travel troubleshooting if something happens.
Wow. Very informative. I will watch more of your videos...under ideal conditions.
You are a very good teacher. Thank you from the bottom of my heart. *.*
Your video is very good. Explainations and diagrams are spot on!!👍👍 Math is also awsome. The one problem I have is you keep calling it watt's law, the correct terminology is ohm's law. I say this with 49 years of electrical experience. I am not trying to bash your presentation because it is quite good, just putting this out there for information purposes. Keep up the great work!!
How about this since it sounds like you're pretty confident... If I link a credible source that states that watts law is Watts = Amps x Volts and Ohms Law is Voltage = Current x Resistance... you send me $100. Sound good?
@@EXPLORISTlife BOOM LOL
You are the best at this. You actually have real life installs verse talking about "how it can be done" from inside a room. Thank you very much for this great information
That was the question I’ve been asking, now that I know how to figure it I can decide what solar panels I need to buy thank you
Best explanation of solar panels I've seen yet!! Thanks!!
Thanks for watching!
Great video Nate, long time follower and I've referenced your material for my own RV solar installation. One way to work around the problem with panels of different voltages and amperages and preserve 100% power efficiency is to wire them into a 2nd charge controller. If budget is a concern and you've already spent $$ on the MPPT controller, the second controller can even be a lower cost PWM controller which will still boost overall power output.
Definitely! That would be moving into a dual array setup, which was a bit out of the scope of this video, in particular and if you wanted/needed to mix solar panel sizes in either of the arrays, they math would remain the same and would be treated as 2 totally seperate arrays. I'll be sure to add a video to my queue for when I talk about solar charge controllers to talk about dual array systems.
@@EXPLORISTlife Nate. If you have not already done so, please include a jump starter video to discuss multiple array systems. You can discuss the reasons why to add a separate array (under it's own SCC) would be considered, and method's of introducing the other array(s) into the current array.
For instance, my system is still patched together kinda rigged. But I do think it is worthy to keep my starter battery (veh battery) charged by the panels while charging my solar system battery. I have thought to just provide the veh battery with it's own mini-array and a cheap PWM SCC, but haven't really prioritized that task just yet.
My other concern regarding multiple arrays (under their own SCC) would be to avoid the blanket affect of shade on all panels connected to the shade affected array. You may have covered this, or Will Prowse did, where if any one part of a panel gets shaded, it, like you indicate regarding the volts/amps affects, can/will affect the entire energy in that entire array assembly. To avoid this, each panel should be given its own SCC so no one panel getting shaded can affect all the other panels if in an Array.
My first guess would be, when having separate arrays with their own SCC would simply be to connect them (ALL) (+ - out wires) to a common terminal effectively turning all them into one main "in".
Not necessarily as sometimes having two separate charge controller not communicating with each other will send a fully charged reading to the second charge. This sometimes will have only one charger pushing current.
@@johnjones1812 Good point. When employing 2 charge controllers it is best to have the same model. If not able to do that the battery parameters must be the same between controllers. No need to communicate then.
@@Robert-jm1kk communication between two chargers is necessary for most efficient charging. I have seen where one charger will float charge or sleep in midday because it's reading the charging voltage from the other charge controller not the actual battery state of charge because they require battery voltage for battery status.
I have tested the same and yes this happens. In order to have proper solar array,we must use equal wattage,voltage,amps and type of panels.
First video explaining solar configuration - you have done a great job creating this. Well done
Glad it was helpful. Cheers!
Hi Nate. Really appreciate your efforts to help us all DIY. I have watched all of your DIY solar videos, some of them multiple times to help me learn solar/RV electrical. I've learned a lot but I'm still not 100% confident in my decisions. I would like to have 2 arrays for my RV. One array will have 4 Renogy 100W (18.6V, 5.38A) panels run in S/P 2/2. These panels will be placed on the ground to get better angles to the sun and to help avoid shading. The other set of panels will be placed on the roof of the RV to allow us to charge while on the road (and in camp), but since placement is more challenging they may get obstructed. I was originally looking at the Renogy 200W but given the array specification differences it seems that their performance would be too low. So based on your advice I changed to using the Rich Solar 200W (37.6V, 5.32A) panels wired in parallel, which if I have done my calculations correctly should get us to 99.8% efficiency. Can you please double-check my logic on this? Thanks. Now for my "real" question - do you think I should use 2 solar charge controllers (say a Victron 100/50 and a Victron 150/60) or would we be better served using one solar charge converter (say a Victron 150/100). The price difference between the two S.C.C. approaches is negligible. Thanks for whatever advice you can provide! Jim
I came across your TH-cam site. Very good explanations on the panels and systems. You have done a very good job on the educational aspects of the web site. Using ABYC as a guide is also brilliant. I wish I had found this 5 years ago when I was exploring solar.
I am retired, used to run a fire LAB and I am now bored a lot. I set up a test rig a few years ago to verify the different types of 12V 100W panels and types of controllers. I used a 4 tube Florent ceiling light fixture for a constant light source. I put the panels on the light source and fed them through both PWM/MPPT controllers. Measured all the outputs, charging times, loads etc. after a few weeks of testing I came up with the best configuration. I charged a 950 Ah lead acid battery, then I would use a 2Kw Inverter to power up 3 100W light bulbs and drained the battery to 11V, then charged it back full. After doing this 15-20 times I was able to calculate the power generation of each panel and efficiency of the controllers. Then moved outside to do sun source testing. Lots of fun was had.
I have a 76 VW Camper. I installed the test solar system on the bus. I have a pair 100W panels in series feeding a cheap MMPT controller. I live in the Pacific NW and all the rain and clouds here are not optimum for solar. Plus the latitude of 48 Deg north means the sun angle is low. The standard 12v panel would not reach charging levels all the time. My testing showed only a couple hours a day they would produce charging voltage when in parallel. So I put the panels in series so when each panel made 7-8 Volts the sum of the voltages will start the charging cycle. Current is low 5-7 amps, but acceptable for this application and this actually works very well in this area. I have a pair of 650Ah Lead acid batteries and they stay full with the system. When the batteries are full the controller shuts off the charge and the panels go to open circuit voltage. The bus is parked most of the time and not used much.
The MPPT controller has a switched load, (like they all do) I am looking to use the excess solar panel power on a restive load after the batteries are full. Since the bus has a refrigerator that runs on Gas/DC/AC. I wired the switched output of the MPPT controller, to the Refrigerator electric heater (12V 1500W) through a diode. I have run this for a few weeks to see how the system will operate. The refrigerator stays cold and occasionally will freeze water on a bright day. This works very well to use the excess power generated so the panel does not sit around at open circuit voltage most of the time. But it's a manual operated, go push the button system. The power is way less than the 1500 watt design but just warm enough to boil the ammonia in the evaporator. I have also wired this into the cheap Chinese diesel heater, it will run on the solar panels alone after it is started and up to temp ( heater fans use 2.5-3.5 amps ) so it will operate on a bright day. It can't start on solar, since the glow plug on start draws 10 amps but after the glow plug cuts out the fan blowers work fine on solar.
Question for you....
Do you know of any MPPT controller that will automatically switch to the "external load mode" when the batteries are full. Or a way to automatically switch with a relay to off load the excess power. If the refrigerator load could be automatically switched, it would run on the solar panels when driving and the alternator is keeping the battery voltage above the MPPT cut off voltage. This is not all that important on this bus, but on larger solar systems, the excess power can be sent to the 1500W heater strip, or maybe a hot water heater element. . On larger RV's this could save the panels from the Open Circuit condition which is not good for the panels. .
Thanks for your time, great job on the solar series.
Although it is indeed possible, load dumping is not something I have experience with. Here is a forum post on the Victron discussion boards that may get you pointed in the right direction: community.victronenergy.com/questions/2089/mppt-dump-load.html
Also... having the panels in 'open circuit condition' is not bad for the panels.
Best tutorials on the Internet great job!
Nate, Thanks for all the work you two have done!
Thanks for watching!
Thank for the video! After watching it an doing some comparisons, I realized I'd get the best watt output if I wired them all in series. Ended up with 250 watts vs previously I was getting something like 100 watts.
Watched 3 of your videos and think you are an excellent instructor who is clear and totally understandable! Bravo
Awesome! Glad it helped. Thanks for watching!
Thanks for the easy to follow explanations. I am learning so much.
I am using 3 solar panels in parallel to charge a 12v car battery. This is used to power up 3-4 leds street lights on the wall. The lights used to stay on till about 4am. The solar panels are not of same size so I think the wire is not right to get the battery charged full. This video helped me to understand the wiring. I will try to correct it.
Thanks I new this but still I wired them wrong. Thanks to your great video I now get more watts out of the same panels. Brains need to be refreshed now and then.
Hey Anders Andersson, Thanks so much! Cheers!
A brilliant video, thanks for the awesome explanation of the results of combining different sized panels.
Nate, you have one of the best DIY sites I have visited. Love your style. I get Volts /Watts / Amps / Parallel / Series. I was missing the part that the MPPT controller actually made the adjustments. Cool, got it.
Awesome! Glad it helped. Thanks for watching!
The Series has been great! Think I've watched everything! Certainly picked up a lot of clue, from tools, to when to fuse on the roof.
What about discussing East / West panels? (when one has no suitable house roof pointing to the equator). I understand that this could be more desirable as one can catch both the early and late sun rays.
One thing you don't seem to have mentioned is that if there is shade on a string - it affects the whole strings production of power - so having a well chosen placement of a mix of Series and Parallel panels can be the wisest configuration.
Lastly (back to East/West configs), if there is less sun on an area - does this affect the voltage or the amperage of the string?
Oh - the hour long video with your friends RV - four panels down each side in series, why that format? I think I'd put the four at the front in series and the four at the back in series - so parking with one end in shade gives at least one good string. The Left & Right strings is primarily beneficial if in the complete open with the RV parked North/South. Perhaps have a method of switching between the two layouts?
Overall a good video to show why you should "not" mix solar panels of different wattage and voltages to a single solar charge. If you have to mix panels of different wattage and voltages place them on separate solar charges. Yes, it may be a little more expensive. But you optimize solar panel output and you will create redundancy. As mentioned in the video a solar array will always be reduced to the efficiency of its lowest rated panels. Always design for optimum production of solar panel arrays. In the end you'll be better off. Also be aware as you increase current you need to increase the wire diameter (lower AWG wire size) which adds both cost and weight. So increase voltage is better than current. And use good quality MPPT charge controller's for higher voltage but keep current low. Let the MPPT solar charger convert the voltage above ~14.6 volts to extra charge current. Finally, have a system properly reviewed by a knowledgeable solar system installer to verify everything is properly sized, from panels, wire runs, charge controller, battery bank and protective breakers. Do everything safe.
That pretty much summed up the last dozen videos on this channel. :)
You mean we can connect two solar charge controllers output together to the one battery bank.
Thanks Bud, I now know why my 160 watt and 100 watt roof panels only produce 11 amps. When plugged in separately I can see 14 amps in ideal conditions. I have a Timber Ridge 24 RKS with the factory solar kit and the portable solar panel plug on the side. When I plug my Go Power 120 watt portable into the side port the two controllers fight and take turns shutting down. I finally bypassed the portable panel controller and plugged it into the third plug on the roof using only one controller and now I can see 15 amps from the 3 panels instead of the 20 amps I can get when totalling individually. I guess I will replace the 100 watt panel with a matching 160 watt panel on the roof and hope my 120 portable has the same voltage. I was wrong to assume the dealer knew what they were doing, lesson learned.
Darn! Well... I'm glad this helped out.
Point of contention: you said, "lowest common denominator," but that cannot be what you meant based on your math. I believe that you meant 'lowest volts (or amp) rating," because the lowest common denominator between 25 and 20 is 5 for the volts [wired in parallel] (and between 8 and 5 is 1 for the amps [wired in series]). Barring that, I am learning a lot through this video. Thanks!
Wow. I've mixed 3 200 watt panels with 4 100 in parallel. So my take away is I've lost 300 watts of power doing that. I've got some wiring to do. Awesome video an explanation of mixed panels. Thank you.
Darn! Hopefully you can get it all sorted out!
@@EXPLORISTlife wired like I described I was getting 49 amp on that controller. But I have a 50 amp an 60 amp. An 1900 watts of panel. Getting 100.6 amp combined. Wired properly I might get 160 amps. Will do a video on it.
Finally found a video explaining this! Thank you!
Thanks for this video
This one give me good knowledge
Ugh, I just made this mistake and added a 100w to a 200w 4x array and knock it down to almost no watts! Thanks Nate!
Oops! Glad it helped.
The best explanation by far. Thanks!
Awesome! Glad it helped. Thanks for watching!
Thanks Nate for providing this very comprehensive and understandable information. I have 48V electric riding mower which I'm setting up with solar, so that it will charge as it is running, thereby extending my range. Unfortunately, through using your online PV/mppt calculator I found out that my pv voltage has to be 5V above that of the 48V battery bank. From a lack of knowledge I assumed I could just have one 100W solar panel push wattage into the bank while driving it. Why does a trickle charging solar panel (the little ones you can buy for RV batteries running at about 10 watts) work on a 12V rv battery, since the voltage of that little panel would be way below the 12V of the rv battery. In my case I'd have to provide at least 300 watts of solar panels (there is no way I can fit that many panels on the support rack I'm building on the mower) in order to actuate the dang mppt controller. Is there any alternative way to push the single 100W into the 48V bank? I see this as a major drawback over a 12V or 24V system in some applications. There should be devices that up-converts (inversion from +- 18V PV voltage to +- 48V battery bank voltage) PV voltage to activate the charger at any time? Any suggestions would be greatly appreciated since I've already put in a lot of time into this built.
Thanks, with your help I able to solve my problems
Happy to help
Your videos are truly excellent.
clear and concise ..thanks for all your hard word ..its much appreciated
Wonderful teaching! Very helpful. This is what I was looking for!
Glad it was helpful. Cheers!
Best explanation on this topic I have run across, and exactly the information I needed to help me configure my ever growing solar system...thank you....aloha
Awesome! Glad it helped. Thanks for watching!
Great video !!
One small correction , it's Ohms law to calculate watts, amps or volts when two values are known.
I'm helping my off grid neighbor who has an assortment of panels and this video answered all my questions.
Good day.
Glad the video helped and I'm sorry for your confustion, but Watts law is: Watts = Amps x Volts as stated in the video.
Ohms law is: Voltage = Current x Resistance
Since we are given Watts, Volts, and Amps; we use Watts Law. We wouldn't use Ohms law as we aren't given resistance nor do we need to know resistance: Introduction to Electronics - Stanford Wiki: ccrma.stanford.edu/wiki/Introduction_to_Electronics - "Watt's Law states that: Power (in Watts) = Voltage (in Volts) x Current (in Amps) P = V I"
Hope this helps!
@@EXPLORISTlife
Thanks for the explanation and I stand corrected.
Continued success with your channel and thanks again for the information.
I am learning so much from this channel, although there are some things that are still a bit fuzzy in my head. QQ.
I own 3-160w EC panels (18.2v*8.8a) and 2-100w panels (17.1v*5.9a) I was looking for a way to combine them with minimal loss.
I think the best possible way under this scenario would be to put them all in a parallel configuration.
Combined AMPs 38.2 * Lowest Volt 17.1 = 653.22 out a 680w. Is that math correct?
your explanations are so clear. thank you
excellent work, very comprehensive and to the point.
Glad it was helpful!
This is a great video! Thank you for giving such a clear and in depth explanation!
Hey Goncalo Valle, Thanks so much! Cheers!
Wow that was the best video ever on this. I actually really understand now
That's awesome! Thanks for watching!
Great videos, direct a quick to the point , and extremely informative, thumbs up every time!!
Hey only1jonnyg, Thanks so much! Cheers!
Excellent. Easy to understand. Thank you for making it easy ☮️🙏☯️
Glad it was helpful!
Thanks for the great and expertly explained information! I wish I’d seen this sooner, but glad I didn’t see it any later
Glad it was helpful!
Thank you for all you do to help people. I do not have my 41 motor home.
Good video as usual. Could you maybe consider making videos on how to use software tools to add batteries and assign inverters as master inverter etc .
Waiting on the future video about when in line fuses are needed. Thanks for good info.
Coming soon!
Exactly what i searched! You are my man!!!
Glad it was helpful. Cheers!
Great tutorial, you are a good teacher!
Hey, The Woodland Companies! I appreciate that. Thanks for watching! 🙂😀
Wish you would cover the impact of partial shade on an array! If one panel of an array is shaded a bypass diode would allow current of a series array to be impacted but would reduce the voltage. Reducing the voltage impacts the performance of panels in parallel to the shaded panel, no?
Man, really great info, love the way you break it down for us!
I guess one way when using different panels is to use a second solar charge controller?
Yes, using 2 controllers will solve problems like that. I do that now even with 4 identical panels using 2 panels on each controller. It was less expensive then buying 1 large controller and if one controlled die I will still be able to get half charge. It also give less trouble with partial shading.
i have 5 identical mppt controllers connected to the same battery bank and i am about to order one more to accomodate an extra 300 watt panel that i cant fit into any other array for reasons mentioned in this video
I appreciate this information... about keeping the panels the same size... and what you explained about adding in a smaller panel, it reduces the overall performance.
My question is
If smaller panels are at the beginning(negative end)of a series, then larger panels are added, is the math the same?
This was a great guide :) I had been pondering on similar problem when using 24v system and using 12v light bulbs and what would happen with mismatched bulbs in series to make 12v work on 24v and came to similar conclusions, had not thought about it when it comes to solar panels and it would be simlar problems... But it is logical when you think about it :)
Glad it was helpful. Cheers!
Very helpful, thanks. How does using something like SolarEdge power optimizers change the equation? I’m assuming it could be substantial as they regulate the power between individual panels helping minimize the effects of partial shade etc. Would appreciate your thoughts. Thanks
Thanks so much for this! Saved my bacon again today. Please keep 'em coming.
You should consider teaching bud, you are spoon feeding me solar stuff ✅🤘🏿
😁🙌 Teaching IS what I'm doing! 🤣👍 I probably couldn't get a teaching job with how poorly I did in school.
I'd like to see an addendum to this video in which you explain the use of separate mini-controllers (I'm not sure that my terminology is correct, but I think you understand the gist of my request).
Great video Nate. Basic electricity at its finest!
What a impressif and informatif video to get on the track, Thank you ! Question : if my understanding is right, can i connect in series 6 X 200 w Renogy panels on 10 Awg cables with a victron charge controller 170-100, and what about the Mc4 connectors good for 30 amp ?
I made my calculation on 95% efficiency of the panels but as we all know i will be lower than that. Thank you!
Thanks for explaining all detail information
Awesome! Glad it helped. Thanks for watching!
Thank you so much for making this make sense.
Nate Awesome way to teach. THAnks!!!
Good video! Just wondering what software do you use to make the diagram?
very nicely explained. very helpful
Glad it was helpful!
Excellent presentation, well explained, thank you.
Glad it was helpful. Cheers!
@@EXPLORISTlife I will be watching this one again and again... I have 3 x 335 for 1,005 and I wanted to add one more over the dining room window for shade and to face South... But unless I get the same one, it looks to be tricky to add on to the three I have>..? I have 3 x 100 amp hours Lithium too
So, now that I'm somewhat confused as to what is the most efficient wiring,for mixed panels,I will be in direct contact in near future for set up help thanks
I'm sorry clear as mud I'll have to watch this over and over....
Or just use like-panels and call it a day. 🙂👍🤣
This is a great explanation.
Hey Patrick York, Thanks so much! Cheers!
Exelent video. Was Very very helpful to me. Thanks alot!
Thanks for the video Nate. Have you considered a video on how to wire the leisure battery to jump the van battery in the event that you drain it, such as when leaving the lights on? This is a topic I cannot find info on but I'm sure many would like to know.
Great idea! I don't have a video for that out, but will be incorporating that into my next van build so will be sure to talk about it.
Look for ANY video about how to jump a car battery! And I really mean any...
Positive (Red) first to be connected. Followed by the negative (Black). Make sure to produce a good contact, with CLEAN poles and clamps!
Start the vehicle. I always let it run for a short while...
Disconnect the negative (black), and finally the positive (red). Be aware of the sequence! A detail many tend to forget!
Easy way to keep it in mind! Red (positive) first and last. The rest in between.
ALWAYS manipulate ONE cable at a time. AND do not hold them together (clamps) under your arm pit while connecting/disconnecting. A colleague literally lost is shirt and had some of his arm pit "fur" burned because of such small detail! LOL 😂
Cheers
Thank you, this was very helpful.
Glad it was helpful! Thanks for watching!
But what questions do you ask to help decide this question? "Wire in parallel or serial?" Only after I answer that question can I start planning. Good vid.
Brilliant ... first clip i begin to understand.
I have just bought a solar system for my camper van.
1x 20amp MPPT solar charge controller
1x 150v VOC 22.5v , VPM 18v, ISC 9.00A , Imp 8.33A
1X100v VOC 21.30v, VPM 17.8, ISC 6.07A, Imp 5.62A
2x 110ah V12 Batteries
SO i am wondering because the solar are different voltages etc what is the best configuration ???
Many thanks and great work on your channel . DJ
Such a clear explanation- thank you. 👏
Glad it was helpful. Cheers!
Pretty fast.
Top. Very good.
Thanks a lot!
New to the channel and solar,(subliminal message) "VxA=W".lol great video.thanks for the panel explanation, was curious on this subject
I liked this twice...
I know this is an older video, but you do such a great job explaining I keep rewatching every time I adjust our solar system. Question: Why do all the Solar Generator forums make it sound like “mix & match” paneling is an absolute No-No? You seem to show it can be done? Is there a difference mix & match to a stand alone MPPT vs an all-in-one SoGen, such as Bluetti or EcoFlow? Thank you..
People think it’s a no-no because they don’t understand or don’t want to learn the math behind the decisions of mismatched solar arrays.
@@EXPLORISTlife Thank you for this.. I had been wondering and have 2 manufacture panels.. but are under paneled so that I don’t Mix & Match.. Good to know it’s possible and now off to do some math!
Good explanation and great graphics! 👍😎
Awesome! Glad it helped. Thanks for watching!
Great videos ! I noticed my charge controller which is rated at 100VDC and 40A there is also a Max input rating of power of 12VDC @520W or 24VDC@1040W. Questions. With this power rating would 20VDC be linear to calculate wattage ? With the power Max input does it matter which configuration is used considering wattage max capacity?
Nate, I have 3 different pannels that I wan to use together, here is the list;
1 - 210 W, 16.77 V, 12.48 A panel
1 - 160 W, 18.53 V, 8.66 A panel
1 - 70 W, 17.2 V, 4.07 A panel
Here is what I came up with;
combine the 160 and 70 in Parallel, resulting in 17.2 V, 12.73 A for 219 W
Then combine the 210 to the other string in Series to net 33.97 V, 12.48 A and 422 W for 95.9%.
What do you think?
Great video!! on the specs of the panels do we use the "Rated DC Voltage" or "Open Circus Voltage" foe the Formula Voltage? Thx
That's awesome. Thank you, Nate.
freaking fantastic. i have space for 4 (maybe 6) x 270 or 300 watt panels and was thinking to add some in the extra space. this is so fruitful to know these plans. for example if i had space for 4 matched panels then added in 2 smaller extra ones but used a different controller to feed the same battery bank how would that work?
Brilliant explanation
Great vid, do you know of an online or spreadsheet tool that you can quickly plug in your existing array and then play with what-if scenarios? Reason I ask I see some vendors with B grade panels for sale and I'd like to add to my SunPower system. Thanks