Regarding Q5: locktite on the bolts shouldn't make much of a difference, however "less steps and less resistance" is wrong. You can look at those two paths as two (very low value) resistors in parallel, together they form a combined path with a smaller resistance than any of them individually. Increase any individual path's resistance, e.g. by adding locktite between metal interfaces, and you increase the combined resistance. Since the combined resistance is never more than the lower resistor value, and brass is a very good conductor, this should have no practical impact.
And any difference in resistance between two paths, will result in an imbalance, since more current will be drawn through cells with lower internal resistance V/R=I V is fixed so increasing R results in less I (current) . Power = V^2R that additional resistance is wasting Power as heat!
Also, when you crank down on the bolt, the threads are GOING to be metal on metal. The liquid lock-tite GTFOs from where the pressure is, and just fills the voids where there would normally be just air. If that's enough to cause any trouble, the system is simply insufficient to begin with.
@@DavidPozEnergy While i do agree with the premiss, thread locker works in fairly small quantities and you have quite a lot of it there. If it spills to the brass mating surface then it will very much so affect the conductivity in a bad way. The cross section of the brass is quite large and there should be no problems with carrying the proposed 50 amps.
Contact resistance between a nut and bolt is so low that it would take thousands of amps to drop a single millivolt across the connection. The nearby crimp connection is far higher contact resistance but it looks like it was done about as well as can be.
Great follow-up! I don't see a problem with the loctite on bolts. I agree that electricity is going to take the path of least resistance, which is brass to ring terminal, not through the bolt. I'm not sure why so many are concerned about that? Unless I'm missing something. That being said, I do think the flange bolt would have been enough on its own as it's got those grooves cut in to help avoid backing out.
Yes, most of the current will take the path of least resistance, but any additional available path will have non-zero current and lower the overall resistance of the joint. Example: One path is 1 milliohms and one path is 2 milliohms. 2/3 of the current will go the first path and 1/3 the second path and the overall resistance will be 2/3 milliohms.
Great video. Couple of things I'd suggest for future ones: 1.) When discussing the threadlocker / no threadlocker, it would have been nice to pop a multimeter across the connection without threadlocker to measure the resistance and then put the threadlocker on and see if you get a higher resistance with the threadlocker on. I'd guess that it makes almost no difference but would be cool to see. 2.) When doing the "nickel test", splitting the salt water solution between two pots and having a nail or similar in one will be a good control and make it clear that rust would have developed in a given time period if there were any iron in the nickel strip. I've subbed and going through all your other content - the TH-cam algorithm did a good job suggesting your channel to me!
The current will chose the least resistance path which will be from the ring terminal to the brass contact. nothing wrong with using locktite as long as it's not all over in between the ring terminal and the brass terminal. When i disassembled my nissan leaf battery pack for the cells, each bolt was threadlocked with blue locktite just as you are using.
Path of lease resistance. Locktite is just fine plus where the threads interlock the glue will be squeezed out by the intense clamping force thus creating a long spiral of little resistance. Hi amp builds may want to solder on the ring terminals in addition to crimping. Great build!!
There are probably a lot of viewers that live in cold weather climate or like me have a motorhome that I use in the winter for snowmobiling and had questions about your low temp cutoff. That's probably the biggest issue that I have about switching to Lithium. Our workshop is an unheated building at 4400 ft elevation. It's cold in the winter with some days never getting above zero. I don't have to worry about our lead-acid batteries unless they discharge to where they would freeze. I have 800 watts of solar and when it's really cold and below zero, the chances are that it is super clear out and solar charging won't be a problem. Thanks for your time to make these videos!
For low temp cutoff, I think many are looking for batteries for rv, or van conversions where heating or conditioned spaces aren’t always possible - or even if it is possible there may be a time when you are out of the rig hiking or tourisming where the heating is not turned on and dips low suddenly or something
@6:40 David. I wold use a lock washer instead of the locktite. There are various locking solutions for your project such as a wavy washer or a nylock nut. But I feel the locking washer should be sufficient provided you torque the nut properly.
Great answers and as an TV, Radio engineer and a past electrician I would not worry about the Loctite. I agree that a loose connection is far more of a possible issue. Thank you
Loctite is a polymer. You are reducing the surface area in contact by 2*2^-2 x H pi D and only using the area of the bolt head - the area of the thread part. I suggest you all do the maths!
Thanks for clarifying what others found as possible issues. Even if their concerns are not found to be an worry, you really did a great job explaining why some solutions or ideas may or may not be necessary.
Loktite the terminals after they are tightened. It will still work by creeping into any gaps between the bolt, the terminal & the crimp, but will not reduce any contact surface area.
David, electricity will follow the shortest path. From the photo you are correct, the juice will flow from the collar to the ring, since that’s where the shortest transfer distance is located. Also, you have more than sufficient contact thickness for the current to easily flow through that ring/collar contact, this would prevent arcing of any sort resulting from insufficient conductivity.
I’m happy to see that everything is working well with your battery. I am sure that you are right about the loctite question.The steel bolt is of lower conductivity than the brass and copper. The area of contact of the copper connector to the terminal looks to me to be at least equivalent to the cross section of the wire bundle, and probably greater. So the current will take the path of least resistance, through the terminal and the connector on the wire. In any case, as another commenter points out, when you tighten the steel bolt, the small amount of loctite will be squeezed so that metal to metal contact will occur between the bolt and terminal threads, since the surfaces of the threads will be microscopically rough. The feedback you got was helpful to prevent possible short circuiting by rubbing and wear between the nickel and the battery cases. Your improvement will ensure that this doesn’t occur. I’m happy that your trusted supplier of nickel sheet was shown to be correct by the lack of corrosion. Someone suggested using a magnet, but nickel is ferromagnetic so that wouldn’t distinguish between iron (Fe) and Nickel (Ni). Resistivity measurements would determine if the Ni was plated onto Fe because of the lower conductivity of Fe. However that would have taken a little more effort to measure than your salt water test. By the way you could have added a lot less salt to the water and it would still have rusted overnight if Fe was at the centre. Good luck with your new battery and thanks for sharing your ideas and methods.
In the electrochemical lab I work in at the technical university of Denmark the contact with pure Nickel is avoided with the use of gloves. The content of Nickel is regulated in consumer products for a reason as Nickel can give you allergies and cause skin rashes. I don't see it as a major safety hazard, but just wanted to let you know regardless 😊
I like your explanation of the current flow through the bolts/terminal and the use of locktite David. That does make sense to me. One could measure this - use two identical terminals with a thin insulator between them, bolt the assembly down using locktite and measure the current in each leg - it doesn't need to be a high current - so a 10A multimeter on each terminal would give you a comparative value of resistance of the top terminal where the current flows through the bolt, threads and locktite and the bottom terminal where the current flows from the terminal block into the terminal face directly. Heck, I can try it here with my 10 amp power supply.
Thanks for the follow up! And for the humble responses. I think your attitude is the best of anyone on YT. My question is, what charger would you recommend for charging this from mains AC power? I have a particular application that requires I let the battery charge during certain hours then discharge during certain hours. Ideally, putting the charger on a timer so it’s just automatic. Thanks!
I charged it with an ISDT Q8 and a 24v power supply. However, that would need manual re-setting. If it's in a permanent location you could run a solar panel to it with a charge controller. Anyways, to your question, probably this: amzn.to/2T5jqp9
On a battery you are supposed to put the high-current leads on the terminal and lower current leads by the bolt. It isn't that the current "wants to flow" but the current will divide proportionally according to the resistance of the paths.
This is what I thought too, electricity will take all paths but at different currents. I believe it's equivalent to a circuit with two resisters. Current will flow through both resisters but at different rates. For example ohms law says I = V/R so if one path has say a 1k ohm resister and we have a voltage of 12v then that path will have 0.012 amps and let's say the other path has a resistance of 10k ohms then that path will have 0.0012 amps. Weather or not the loctite is safe I would think would depend on how much resistance it had the load on the battery and at what temperature it would start to fail. Just my .02 but I think it backs up your statement.
Great detail between the two videos! And thanks for actually testing the low temperature cutoff -- a lot of BMS's have that as a listed feature, but don't seem to work. (I can only imagine how the discussion went to clear the freezer like that! 🤣👍)
You never mentioned what you are going to use it on. When I built relays that went into space we used conductive silver epoxy on threaded connections. I would put some dessicant inside and a usb adapter port too. A led light on the side would work too.
I commented on your last video about using foam spacers between the battery and the box. That would be a better thermal insulator than a cutting board. You might want to check out "film heater" elements available on-line to put between the foam and the cells. They should be able to keep the cells above 50F in most cold weather.
The metal surfaces will make metallic contact where they are tightened. The locktite will glue the gaps on the opposite site where there is no metallic contact. So don’t worry about the application of locktite.
Gonna see these on the market soon? BattlePoz, DavidBorn. ;-). Both videos are super informative! As always! Note: My Valance batteries all had Locklite on the bolt threads...and that was from the factory.
Hello,for all the non electrical people who view your channel, can you kindly tell us what this build will be used for,what are the possible applications, it's totally weight when build is finished,how long this will last before it goes dead? This build can power what? And for how long? Examples of what it can power up and estimated duration? Thanks! Awesome video of the complete build!
Great set of experiments. I agree with you on the Loc-tite, the threads would be a bad path for current flow and the surface of the lug to connector would be the path of lowest resistance.
Dont see an issue on a little locktite on the THREAD of the bolt, just as you did. That is where its needed anyway. Another way to check for pure nickel is to put it on a grinder (benchgrinder, anglegrinder, linisher....) nickel plated steel will spark as soon as you go through the nickel plating. Pure Nickel won't spark. Keep up the good work.
For the temperature sensing - Thermistors on the BMS board are necessary to ensure the electronics do not get too hot. It would be nice if the BMS manufacturer had a couple of inputs for thermistors that were attached to a couple of the cells. Cells and BMS board will heat up at different rates. For the battery safety and performance, you care more about the actual cell temperatures. If you demo some of the simple power tool batteries, they have sensors attached to the outside of the cells as an example (those NIMH or NICAD cell BMS use the cell temperature as a secondary input to control the end of charge). Dave - Keep up with your battery builds! Good work and good videos too. (Have to comment on the battery in the family freezer. My wife hates it when I do that kind of stuff)
Dave, just use your multimeter to test the resistance from the lead to the top of the terminal on the other side with and without the Loctite(or before you install the Loctite). That way you know for sure. I bet it won't even register a difference.
Most cheap multimeters won't measure that small value of a resistance. You will have more resistance in the meter connections and leads. Maybe with some expensive 4 wire meter measurement to measure those values. I don't know the equipment that you have available but most hobby folks don't invest that sort of money. I have one of those cheap meters used in this video and its good value for money, but forget trying to measure those sort of micro ohm values. I've invested in a variety of test equipment for my lab and your talking big bucks. That meter is a throw away chinese meter for just general use not accurate measurement and certainly not to measure the low ohm readings to see what's really going on there.
@@KB1UIF For sure. Need a mho's meter lol!!! Easiest way is put insulator under head of bolt. DC volts lowest scale (millivolts or uv) - test from top of bolt to terminal.
The battery looks really good for a diy. After I looked for quite awhile; i ended up with the Battle Born. (which was not my first choice by any means). I would have gone with the Fortress or the Simpliphi lithium batteries, but the cost, weight, and shipping cost was a deal breaker for me. Battle Born ended up giving me a good deal on the cost per battery, so I took it. Also the ten year warranty helps too.......
Time and effort and the price to suspend is not worth it I recommend you should buy from the reliable factory with the five or 10 years warranty what do you think?
The only thing I might consider doing is adding a couple of silica gel packets into the case of the battery if you should ever require exposure to cold. Dropping the battery into the freezer causes the air/humidity in the box to pass through the condensation point. Having standing moisture on the contacts/components is something I'd be worried about. Once the battery warms up all those little frozen droplets will flow before they evaporate so you could get an electrical short.
Great follow-up! I'm gonna check out that video of the gentleman from VT that you recommend. I just moved to VT from MA and I would like to go off grid next spring.
AWESOME build and attention to detail....they don't make them like that in China! ...would be so kind as do a follow up after the battery has had maybe 500 cycles and show us how its capacity is holding up? Keep up the great work, Cheers Pete
The threads will pull up, squeezing and loctite out of the way and making good metal to metal contact. This will be a current path parallel to the 'crimp-brass' junction. It's insignificant you'll have more resistance in the 'wire-crimp' junction. I'd be more concerned about galvanic corrosion between the dissimilar metals. I once had a lead-acid battery with just 20 amps flowing and there was a 100mV drop across the 'post-terminal' junction. The slightest of movement cleared this, but it's something I keep a close eye on now.
Loctite on the threads is not an issue. Threads only engage by around 60 - 70% anyway. Once the bolt is torqued all the Loctite will be squashed out of the part of the treads that actually make contact. Also the terminal is squashed down hard onto the top of the battery post. If the Loctite is a problem, the terminals will get hot during a heavy discharge, and they don't.
I believe the way to determine whether the loctite on the threads is significant would be to determine the surface area of the lug-to-ring connection. If that cross section is greater than the wire's cross section then the connection should not be a bottleneck.
The threads have nil to do with your connection. It is all about lug to brass connection. PS the lugs you are using are primarily designed for a solder joint not compression. That's why they have no hole in the bottom of the wire sleeve part. Although you can use them for compression. Pleased to see you using a good compression tool.
You could also use Nordlock washers instead of loctite, though I don't think the loctite would cause any problem. I have some CALB large format 100 Ah LFP cells which came with a dry type of thread locker already on the threads so at least they don't think that type would cause an issue.
First off. Awesome project! I definitely want to build one of these. Or two... 😂. Maybe I missed it. How much did this cost to make in the end? I like the switch idea, but wouldn’t the bms shut it down anyway in an over heat situation charging? Let us know if you ever see the breaker trip. It may be a cool test. 😎I also see a battery off button on your app. Does it work? Ps, i think you are right about the loctite. Even if the electricity did pass through the bolt the loctite takes up space behind the threads. The torqued side still contacts.
$440. The parts list and prices are at the very end of the video. Yes, the BMS is probably going to shut down faster than the breaker can trip. It's something I like doing so I can wire everything with no voltage, then check everything, torque all my connections, then turn it on.
As far as loctite - it's going to fill gaps in the threads, the bolt isn't going to just be floating in a sea of loctite. When you torque it down the threads of the bolt will pull against the "nut" and create plenty of connections. That said - loctite is really not necessary in a non moving part like this, especially if you toss a locking type washer on it.
Thanks for the very good videos. Please excuse for my ignorance. I have 2 questions. 1) Why is nickel used for the conductors and not other materials such as copper? 2) Why are cells (within a 20 cell bank) connected in parallel directly? I thought any voltage difference would cause high current among the cells.
Nickel can be spot welded with small homeowner level spot welders. Copper is very hard to spot weld and would require an industrial machine. 2. We connect cells in parallel to increase capacity. If I only had 4 cells in series this would be a 5ah pack (small). but at 20p4s, this is 100ah. It's true that different voltage between cells could cause current to flow. That's why in my previous video I checked the voltage of every single cell before spot welding them together. As I said in that video, I needed every cell within 0.10 volts of each other, and they were.
@@DavidPozEnergy Thanks for the prompt reply. Even with potential differences less than 0.1 volt, I imagine the cells are continuously trying to level each other. I worry about the current and heat are damaging the cells. (For the same reason, when I was still at school, the teacher told us not to connect power supplies in parallel.) Am I worrying too much?
David, great job and excellent format. Would love to see you do more of this type of video on some of your builds. I have a question. When you use DALY BMS'S, is there some way or program you can use to check the cell levels?
The newer Daly's have a bluetooth option, but not older ones. I have plenty of older Daly BMS's in service. Take a look at my Ammo can build. I soldered in two extra JST-XH connectors. They allow me to manually check the cells fast with a little device called a Batt-Go cell checker. I do that once in a while because it's fun, but the BMS is the protection 24/7
Nice video, thanks for producing this. I was the build video and now I know how my nevt build looks. Just one question. Is there a limit to how many of the batteries you can connect in parallel?
If you load the battery and touch from the ring terminal to the brass with a test light, you will know if it's an issue. The test light will light up if you have too much resistance in the connection. If it does not, the connection is fine. That's the test that has been being used in the automotive industry for longer than I have been around. Takes opinion out of it. Keep it simple.
It sounds so simple to have your battery in a heated environment. Those of us who have remote cabins in cold weather areas and don't live in the structure, that is not so easy or should I say.........impossible. This is presently being addressed by the leading commercial battery manufacturers and I expect within a year this will become practically a non-issue. However, this issue kept me from going LiFePO when I bought new batteries for the cabin 15 months ago. The advancement of the technology surrounding this chemistry evolves so rapidly it is amazing.
I always used locktite when I competed in car audio 5 farad cap and 3 batteries with 2 150 amp alternators. Needed it or everything would come loose. Busted the front window and blow the sunroof out a few times
Have you considered using spacers and using a fan to circulate air through the battery? Wouldn't batteries in the middle be most likely to get hotter than the outside due to insulation? A Simple PC fan could keep things cooler - or warmer depending on the setup..?
Sure. There is nothing wrong if you want to incorporate some form of cooling. Most electric vehicles have to do this since they are trying to push 300+ amps out of the cells. In my case I built this for small off grid stuff, like lights and mini-fridge. I just won't be pulling enough amps to create excess heat.
All fine, your builds are low voltage and amperage ones there this simply not matter. Good job, nice engineering. Electrons like to travel as close as possible to surface or even on the surface of conductor all depends on voltage and amperage. My apologies for non-professional wording but i tried to dumb it down for average as possible.
The best thing for you contacts would be Humiseal. Don't use Locktide, torque the contacts correct and then apply a thin layer of Humiseal. Thats protect you contacts for corrosion and loosing. Its always used in the Aircraft Industry for the electrical connectors with thermal lugs. A added spring washer will help you to lock the screw.
Thank you so much for sharing your videos! I don't know if someone already posted this question, can lithium battery to be built as a deep cycled one to be used in motorhome chassis battery? What need to be cared for? Thanks!
It would be useful to know how many man hours you expended on this project. Obviously, subsequent battery builds would be faster. If someone were to build 4 to 8 batteries, an estimate could be made regarding total man hours, with an estimated efficiency increase in later builds. This provides a useful aid in deciding whether or not to build your own, or buy Battleborn. Victron, or other brand batteries. Some have more time than money. For some, the satisfaction of DIY is worth it both for knowledge and competence, even if buying would make more sense. For those less technically competent, buying is obviously the better option. Those choosing to watch these videos likely have higher competence in attempting DIY. Thank you for helping feed our technical curiosity.
I wouldn't mind building another as a speed test, but these builds get expensive. $440 in parts. I need to wait for the views, and next months ad revenue before buying more materials.
Cool video. But at $477 for 1 battery? I understand that LiFePO4s are expensive. Last summer I used 1450 KWh in one month. I would need MANY of them to do what I need. Good luck with yours.
I noticed you didn't put Locktite in all the threads leaving part of the threads clean to conduct power. Since it doesn't cover all the threads I doubt conducting power in the threads will be a problem. Especially as you point out a lot of power can pass through directly from the side of the terminal. The only way I can see it could possibly make a difference is with extremely high current loads.
Nice! Currently building an approximately 100AH lithium for a trolling motor, I can't see spending $900+ for a dang battery! But for less weight and FAR less cost (half the size of your battery) I can DOUBLE my water time! Certainly blows away using 18650 batteries!!
i luv ur lids... ty i was wondering ... could ur build be stackable in both parallel or series configuration..? ... where did u source ur case..? ... How long dose it take to charge from cut off to full charge..? ... would this be safe to keep in my home full time? its cold here...
Yes, you can series and parallel them. I bought the case from Aliexpress. It can be charged in 2 hours (faster without the circuit breaker). It is one of the safest lithium chemistries. However, I still recommend storing batteries in an out-building (shed or garage).
I've had a concern for some time as to whether a battery system can heat itself from power from the batteries to keep from low temperature concerns. (When in an insulated compartment, of course!) Then, does the increased battery efficiency from self-heating translate to a net gain or a net loss of battery capacity?
The only problem i see with the lock tight would be i would put it into the hole rather then on the stud... that way if there is any "extra" lock tight it would be pushed into the connection rather then building up at the top maybe building a small film between the brass and your ring connection
@@DavidPozEnergy RV off-grid camping is probably the biggest driver, since everything factory is 12V it's pretty expensive to convert to 24 or 48V. I looked into using DC-DC converters because you can get used 48V packs pretty inexpensively but a converter that can handle the 60A charging current from the converter is not cheap, especially if it has to be outdoor rated.
No, for $100 more than I spent in parts you can buy a pre-built battery. Lots of great options have come on the market this past year. Personally, I'd get this one: shop.signaturesolar.us/products/12v-100ah-lifepo4-battery-by-eg4?ref=4_rHcgZ9x-TiF-
The short answer is yes. But, there is a risk of blowing the fuse on your cigarette lighter because if the lithium battery is low, like 12v, and your alternator puts out 14v, then it might draw high amps. And if you connect it directly to the alternator, you may burn out the alternator. A safer way to charge is to use a 12v-12v charger. Like this one: amzn.to/3hCZ423 (affiliate link)
I really liked this video. Now I'm curious if anyone has built this for high power draw use and designed active cooling. I'm tempted to use this design for an EV and design the system for easy swap out of batteries instead of charging in situ. Nobody is doing this commercially, which leaves me wondering if the logistics of swapping out batteries is not worth the effort.
By the time you've built a battery (even a LiPO battery) for a decent range, you are looking at a fairly hefty (got an engine hoist handy? heavy) battery. I've seen plans for such things, but they always cite the weight of the battery and the challenge of making a high capacity quick connect as the big failings.
I think if you put the loctite on the bolt it could run out/squish and coat the surface of the brass part that is in your circuit, potentially not great. Solution, just put the loctite on the inside screw thread (not the bolt), and not have so much that it would squish out. Then the brass surface stays clean!
Thank you Mr David pause for your excellent content. I'm looking to find out more about the battery box you have? I looked over on 18615 Ed and did not see any there period could you give more detail on the Alley Express information such as a link company name or anything else I can lead us to finding it thank you
If you message Keith, at 18650'ed, he has them and can ship it out, he just doesn't have them listed yet. But the one I bought on Aliexpress: www.aliexpress.com/item/33030465274.html?spm=a2g0o.productlist.0.0.30436455ktYQrF&algo_pvid=139964d4-2b71-461d-a3a1-ac25f5cc9a8a&algo_expid=139964d4-2b71-461d-a3a1-ac25f5cc9a8a-2&btsid=0bb0623416030517225768406e4b30&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
In regards to not wanting the bolt to come out, and with how "built to last" you've done everythying... .once you are happy and ready to close it up for good.. they make conductive epoxy... you could use that rather than threadlock
I'm not sure you fixed the potential short issue with the card under the positive end. The nickel was bent over the edge of the cells so at the very edge it could still rub through the shrink wrap. Your insulation should have gone around the edge of the cells.
Some people do, but I don't because you have to be super fast with your soldering skills not to over-heat the cell. I'm not very good at soldering, so I bought the spot welder.
I don't know about the magnet. But for copper... I have a coil of nickel plated copper and tried to get it to stick, but couldn't. Not sure what kind of high-tech welders are used for it, but not my hobby spot welder.
Nickel is one of only four metals that are ferromagnetic, meaning they are attracted to magnets and are magnetic themselves. The others are iron, cobalt and gadolinium.
Could you explain how do you charge you battery ? I saw your Mean Well Model RSP power supply. Do you use any buck or boost with CC/CV converter in between ?
Yes, I have a variety of different buck and boost converters depending on what I'm doing. For this I was using my ISDT Q8, which is a hobby charger, and the 24v power supply.
Regarding Q5: locktite on the bolts shouldn't make much of a difference, however "less steps and less resistance" is wrong.
You can look at those two paths as two (very low value) resistors in parallel, together they form a combined path with a smaller resistance than any of them individually.
Increase any individual path's resistance, e.g. by adding locktite between metal interfaces, and you increase the combined resistance.
Since the combined resistance is never more than the lower resistor value, and brass is a very good conductor, this should have no practical impact.
Thank you for the clear visual explanation. Makes a lot more sense now.
And any difference in resistance between two paths, will result in an imbalance, since more current will be drawn through cells with lower internal resistance V/R=I V is fixed so increasing R results in less I (current) . Power = V^2R that additional resistance is wasting Power as heat!
Also, when you crank down on the bolt, the threads are GOING to be metal on metal. The liquid lock-tite GTFOs from where the pressure is, and just fills the voids where there would normally be just air. If that's enough to cause any trouble, the system is simply insufficient to begin with.
@@DavidPozEnergy While i do agree with the premiss, thread locker works in fairly small quantities and you have quite a lot of it there. If it spills to the brass mating surface then it will very much so affect the conductivity in a bad way. The cross section of the brass is quite large and there should be no problems with carrying the proposed 50 amps.
Contact resistance between a nut and bolt is so low that it would take thousands of amps to drop a single millivolt across the connection. The nearby crimp connection is far higher contact resistance but it looks like it was done about as well as can be.
Great follow-up! I don't see a problem with the loctite on bolts. I agree that electricity is going to take the path of least resistance, which is brass to ring terminal, not through the bolt. I'm not sure why so many are concerned about that? Unless I'm missing something. That being said, I do think the flange bolt would have been enough on its own as it's got those grooves cut in to help avoid backing out.
Yes, most of the current will take the path of least resistance, but any additional available path will have non-zero current and lower the overall resistance of the joint. Example: One path is 1 milliohms and one path is 2 milliohms. 2/3 of the current will go the first path and 1/3 the second path and the overall resistance will be 2/3 milliohms.
Great video.
Couple of things I'd suggest for future ones:
1.) When discussing the threadlocker / no threadlocker, it would have been nice to pop a multimeter across the connection without threadlocker to measure the resistance and then put the threadlocker on and see if you get a higher resistance with the threadlocker on. I'd guess that it makes almost no difference but would be cool to see.
2.) When doing the "nickel test", splitting the salt water solution between two pots and having a nail or similar in one will be a good control and make it clear that rust would have developed in a given time period if there were any iron in the nickel strip.
I've subbed and going through all your other content - the TH-cam algorithm did a good job suggesting your channel to me!
The current will chose the least resistance path which will be from the ring terminal to the brass contact. nothing wrong with using locktite as long as it's not all over in between the ring terminal and the brass terminal.
When i disassembled my nissan leaf battery pack for the cells, each bolt was threadlocked with blue locktite just as you are using.
And thread locker will go in the spaces between metals part, not where metal contact metal to let the current flow... Thanks for the update David :)
Lets be specific - Current follows ALL paths simultaneously. The amount of current will be proportional to the path resistance.
Any additional path available to the current will lower the overall resistance of the joint
@@TrackGeekslol! I say this exact phrase. Its correct though
Path of lease resistance. Locktite is just fine plus where the threads interlock the glue will be squeezed out by the intense clamping force thus creating a long spiral of little resistance. Hi amp builds may want to solder on the ring terminals in addition to crimping. Great build!!
There are probably a lot of viewers that live in cold weather climate or like me have a motorhome that I use in the winter for snowmobiling and had questions about your low temp cutoff. That's probably the biggest issue that I have about switching to Lithium. Our workshop is an unheated building at 4400 ft elevation. It's cold in the winter with some days never getting above zero. I don't have to worry about our lead-acid batteries unless they discharge to where they would freeze. I have 800 watts of solar and when it's really cold and below zero, the chances are that it is super clear out and solar charging won't be a problem. Thanks for your time to make these videos!
For low temp cutoff, I think many are looking for batteries for rv, or van conversions where heating or conditioned spaces aren’t always possible - or even if it is possible there may be a time when you are out of the rig hiking or tourisming where the heating is not turned on and dips low suddenly or something
@6:40 David. I wold use a lock washer instead of the locktite. There are various locking solutions for your project such as a wavy washer or a nylock nut. But I feel the locking washer should be sufficient provided you torque the nut properly.
Great answers and as an TV, Radio engineer and a past electrician I would not worry about the Loctite. I agree that a loose connection is far more of a possible issue. Thank you
Loctite is a polymer. You are reducing the surface area in contact by 2*2^-2 x H pi D and only using the area of the bolt head - the area of the thread part. I suggest you all do the maths!
Thanks for clarifying what others found as possible issues. Even if their concerns are not found to be an worry, you really did a great job explaining why some solutions or ideas may or may not be necessary.
Loktite the terminals after they are tightened. It will still work by creeping into any gaps between the bolt, the terminal & the crimp, but will not reduce any contact surface area.
David, electricity will follow the shortest path. From the photo you are correct, the juice will flow from the collar to the ring, since that’s where the shortest transfer distance is located. Also, you have more than sufficient contact thickness for the current to easily flow through that ring/collar contact, this would prevent arcing of any sort resulting from insufficient conductivity.
My goodness, most of all these were in the video, i can only imagine the comments you deal with. Great video
I’m happy to see that everything is working well with your battery. I am sure that you are right about the loctite question.The steel bolt is of lower conductivity than the brass and copper. The area of contact of the copper connector to the terminal looks to me to be at least equivalent to the cross section of the wire bundle, and probably greater. So the current will take the path of least resistance, through the terminal and the connector on the wire. In any case, as another commenter points out, when you tighten the steel bolt, the small amount of loctite will be squeezed so that metal to metal contact will occur between the bolt and terminal threads, since the surfaces of the threads will be microscopically rough. The feedback you got was helpful to prevent possible short circuiting by rubbing and wear between the nickel and the battery cases. Your improvement will ensure that this doesn’t occur. I’m happy that your trusted supplier of nickel sheet was shown to be correct by the lack of corrosion. Someone suggested using a magnet, but nickel is ferromagnetic so that wouldn’t distinguish between iron (Fe) and Nickel (Ni). Resistivity measurements would determine if the Ni was plated onto Fe because of the lower conductivity of Fe. However that would have taken a little more effort to measure than your salt water test. By the way you could have added a lot less salt to the water and it would still have rusted overnight if Fe was at the centre. Good luck with your new battery and thanks for sharing your ideas and methods.
In the electrochemical lab I work in at the technical university of Denmark the contact with pure Nickel is avoided with the use of gloves. The content of Nickel is regulated in consumer products for a reason as Nickel can give you allergies and cause skin rashes. I don't see it as a major safety hazard, but just wanted to let you know regardless 😊
Thanks! Didn’t know this.
I like your explanation of the current flow through the bolts/terminal and the use of locktite David. That does make sense to me. One could measure this - use two identical terminals with a thin insulator between them, bolt the assembly down using locktite and measure the current in each leg - it doesn't need to be a high current - so a 10A multimeter on each terminal would give you a comparative value of resistance of the top terminal where the current flows through the bolt, threads and locktite and the bottom terminal where the current flows from the terminal block into the terminal face directly. Heck, I can try it here with my 10 amp power supply.
Wow... that was an EXCELLENT IDEA!
That BMS low temperature protection test was pretty nice, thanks for sharing
Thanks for the follow up! And for the humble responses. I think your attitude is the best of anyone on YT.
My question is, what charger would you recommend for charging this from mains AC power? I have a particular application that requires I let the battery charge during certain hours then discharge during certain hours. Ideally, putting the charger on a timer so it’s just automatic. Thanks!
I charged it with an ISDT Q8 and a 24v power supply. However, that would need manual re-setting. If it's in a permanent location you could run a solar panel to it with a charge controller.
Anyways, to your question, probably this: amzn.to/2T5jqp9
DavidPoz thank you!
On a battery you are supposed to put the high-current leads on the terminal and lower current leads by the bolt.
It isn't that the current "wants to flow" but the current will divide proportionally according to the resistance of the paths.
This is what I thought too, electricity will take all paths but at different currents. I believe it's equivalent to a circuit with two resisters. Current will flow through both resisters but at different rates. For example ohms law says I = V/R so if one path has say a 1k ohm resister and we have a voltage of 12v then that path will have 0.012 amps and let's say the other path has a resistance of 10k ohms then that path will have 0.0012 amps. Weather or not the loctite is safe I would think would depend on how much resistance it had the load on the battery and at what temperature it would start to fail. Just my .02 but I think it backs up your statement.
Mr David the only problem that I see is no problem you are a champion love your work keep it up on Joy all of your show's thank you very
Great detail between the two videos! And thanks for actually testing the low temperature cutoff -- a lot of BMS's have that as a listed feature, but don't seem to work. (I can only imagine how the discussion went to clear the freezer like that! 🤣👍)
David, glad to see you implemented some of the changes people were mentioning from the last video. Hope the battery has a long and safe life.
You never mentioned what you are going to use it on. When I built relays that went into space we used conductive silver epoxy on threaded connections. I would put some dessicant inside and a usb adapter port too. A led light on the side would work too.
I'm also a big fan of renewable / alternative energy so I really like your vids and your sharing of knowledge. Thanks for the vids keep em coming.
I commented on your last video about using foam spacers between the battery and the box. That would be a better thermal insulator than a cutting board.
You might want to check out "film heater" elements available on-line to put between the foam and the cells. They should be able to keep the cells above 50F in most cold weather.
Love your content Dave. Really appreciate your reception to feedback, it helps all us DIYers.
The metal surfaces will make metallic contact where they are tightened. The locktite will glue the gaps on the opposite site where there is no metallic contact. So don’t worry about the application of locktite.
I’m pleased you sorted that main wire out mate. Happy days 👍🏽😁 I wouldn’t want that 🔥 to happen mate. Take care and your family 👍🏽
You are correct. The current will ALWAYS take the path of least resistance.
Love your channel + comment about sharing / FUN! Agreed!
Great follow up. Nice and QUICK
Gonna see these on the market soon? BattlePoz, DavidBorn. ;-). Both videos are super informative! As always! Note: My Valance batteries all had Locklite on the bolt threads...and that was from the factory.
I agree the threads only purpose is to hold the screw in place. The brass is doing the work.
Fantastic build. And love your workshop!
6:13.. You are absolutely correct David. BTW... Great tests..
Thank you David, great job
Hello,for all the non electrical people who view your channel, can you kindly tell us what this build will be used for,what are the possible applications, it's totally weight when build is finished,how long this will last before it goes dead? This build can power what? And for how long? Examples of what it can power up and estimated duration? Thanks! Awesome video of the complete build!
Great set of experiments. I agree with you on the Loc-tite, the threads would be a bad path for current flow and the surface of the lug to connector would be the path of lowest resistance.
Dont see an issue on a little locktite on the THREAD of the bolt, just as you did. That is where its needed anyway.
Another way to check for pure nickel is to put it on a grinder (benchgrinder, anglegrinder, linisher....) nickel plated steel will spark as soon as you go through the nickel plating. Pure Nickel won't spark.
Keep up the good work.
Good catch! Excellent idea!
For the temperature sensing - Thermistors on the BMS board are necessary to ensure the electronics do not get too hot. It would be nice if the BMS manufacturer had a couple of inputs for thermistors that were attached to a couple of the cells. Cells and BMS board will heat up at different rates. For the battery safety and performance, you care more about the actual cell temperatures. If you demo some of the simple power tool batteries, they have sensors attached to the outside of the cells as an example (those NIMH or NICAD cell BMS use the cell temperature as a secondary input to control the end of charge).
Dave - Keep up with your battery builds! Good work and good videos too. (Have to comment on the battery in the family freezer. My wife hates it when I do that kind of stuff)
Dave, just use your multimeter to test the resistance from the lead to the top of the terminal on the other side with and without the Loctite(or before you install the Loctite). That way you know for sure. I bet it won't even register a difference.
Most cheap multimeters won't measure that small value of a resistance. You will have more resistance in the meter connections and leads.
Maybe with some expensive 4 wire meter measurement to measure those values.
I don't know the equipment that you have available but most hobby folks don't invest that sort of money. I have one of those cheap meters used in this video and its good value for money, but forget trying to measure those sort of micro ohm values.
I've invested in a variety of test equipment for my lab and your talking big bucks. That meter is a throw away chinese meter for just general use not accurate measurement and certainly not to measure the low ohm readings to see what's really going on there.
@@KB1UIF For sure. Need a mho's meter lol!!! Easiest way is put insulator under head of bolt. DC volts lowest scale (millivolts or uv) - test from top of bolt to terminal.
The battery looks really good for a diy. After I looked for quite awhile; i ended up with the Battle Born. (which was not my first choice by any means). I would have gone with the Fortress or the Simpliphi lithium batteries, but the cost, weight, and shipping cost was a deal breaker for me.
Battle Born ended up giving me a good deal on the cost per battery, so I took it. Also the ten year warranty helps too.......
Time and effort and the price to suspend is not worth it I recommend you should buy from the reliable factory with the five or 10 years warranty what do you think?
For sure. I'm amazed how fast prices have dropped the last couple years. I would buy a pre-built one for $500 today.
The only thing I might consider doing is adding a couple of silica gel packets into the case of the battery if you should ever require exposure to cold. Dropping the battery into the freezer causes the air/humidity in the box to pass through the condensation point. Having standing moisture on the contacts/components is something I'd be worried about. Once the battery warms up all those little frozen droplets will flow before they evaporate so you could get an electrical short.
Maybe oxygen absorber also.
Great follow-up! I'm gonna check out that video of the gentleman from VT that you recommend. I just moved to VT from MA and I would like to go off grid next spring.
AWESOME build and attention to detail....they don't make them like that in China! ...would be so kind as do a follow up after the battery has had maybe 500 cycles and show us how its capacity is holding up? Keep up the great work, Cheers Pete
The threads will pull up, squeezing and loctite out of the way and making good metal to metal contact.
This will be a current path parallel to the 'crimp-brass' junction. It's insignificant you'll have more resistance in the 'wire-crimp' junction.
I'd be more concerned about galvanic corrosion between the dissimilar metals. I once had a lead-acid battery with just 20 amps flowing and there was a 100mV drop across the 'post-terminal' junction. The slightest of movement cleared this, but it's something I keep a close eye on now.
Loctite on the threads is not an issue. Threads only engage by around 60 - 70% anyway. Once the bolt is torqued all the Loctite will be squashed out of the part of the treads that actually make contact. Also the terminal is squashed down hard onto the top of the battery post. If the Loctite is a problem, the terminals will get hot during a heavy discharge, and they don't.
I believe the way to determine whether the loctite on the threads is significant would be to determine the surface area of the lug-to-ring connection. If that cross section is greater than the wire's cross section then the connection should not be a bottleneck.
I think you are correct about ring terminals conducting more than threads on bolt.
The threads have nil to do with your connection. It is all about lug to brass connection.
PS the lugs you are using are primarily designed for a solder joint not compression. That's why they have no hole in the bottom of the wire sleeve part. Although you can use them for compression. Pleased to see you using a good compression tool.
A bolt getting lose can produce more heat at connection then worrying about if lock tight not getting enough contact between post and cable end
You could also use Nordlock washers instead of loctite, though I don't think the loctite would cause any problem. I have some CALB large format 100 Ah LFP cells which came with a dry type of thread locker already on the threads so at least they don't think that type would cause an issue.
First off. Awesome project! I definitely want to build one of these. Or two... 😂. Maybe I missed it. How much did this cost to make in the end? I like the switch idea, but wouldn’t the bms shut it down anyway in an over heat situation charging? Let us know if you ever see the breaker trip. It may be a cool test. 😎I also see a battery off button on your app. Does it work?
Ps, i think you are right about the loctite. Even if the electricity did pass through the bolt the loctite takes up space behind the threads. The torqued side still contacts.
$440. The parts list and prices are at the very end of the video.
Yes, the BMS is probably going to shut down faster than the breaker can trip. It's something I like doing so I can wire everything with no voltage, then check everything, torque all my connections, then turn it on.
@@DavidPozEnergy that’s quite a savings! Thanks!
Great video, I just want to add that you need oxigen, not just salt water, to rust any steal element. Just saying.
Correct.
Think you need a "control piece" in the "corrosion bath". I agree that a "magnet test" might also yield some valuable data...
As far as loctite - it's going to fill gaps in the threads, the bolt isn't going to just be floating in a sea of loctite. When you torque it down the threads of the bolt will pull against the "nut" and create plenty of connections.
That said - loctite is really not necessary in a non moving part like this, especially if you toss a locking type washer on it.
Thanks for the very good videos. Please excuse for my ignorance. I have 2 questions. 1) Why is nickel used for the conductors and not other materials such as copper? 2) Why are cells (within a 20 cell bank) connected in parallel directly? I thought any voltage difference would cause high current among the cells.
Nickel can be spot welded with small homeowner level spot welders. Copper is very hard to spot weld and would require an industrial machine. 2. We connect cells in parallel to increase capacity. If I only had 4 cells in series this would be a 5ah pack (small). but at 20p4s, this is 100ah. It's true that different voltage between cells could cause current to flow. That's why in my previous video I checked the voltage of every single cell before spot welding them together. As I said in that video, I needed every cell within 0.10 volts of each other, and they were.
@@DavidPozEnergy Thanks for the prompt reply. Even with potential differences less than 0.1 volt, I imagine the cells are continuously trying to level each other. I worry about the current and heat are damaging the cells. (For the same reason, when I was still at school, the teacher told us not to connect power supplies in parallel.) Am I worrying too much?
David, great job and excellent format. Would love to see you do more of this type of video on some of your builds. I have a question. When you use DALY BMS'S, is there some way or program you can use to check the cell levels?
The newer Daly's have a bluetooth option, but not older ones. I have plenty of older Daly BMS's in service. Take a look at my Ammo can build. I soldered in two extra JST-XH connectors. They allow me to manually check the cells fast with a little device called a Batt-Go cell checker. I do that once in a while because it's fun, but the BMS is the protection 24/7
Any junction will conduct, the spade on the end of that cable will conduct current from the brass contact and the bolt.
Thanks for the follow up.
Nice video, thanks for producing this. I was the build video and now I know how my nevt build looks. Just one question. Is there a limit to how many of the batteries you can connect in parallel?
If you load the battery and touch from the ring terminal to the brass with a test light, you will know if it's an issue. The test light will light up if you have too much resistance in the connection. If it does not, the connection is fine. That's the test that has been being used in the automotive industry for longer than I have been around. Takes opinion out of it. Keep it simple.
Exactly. Good catch - I mean damn... I face palmed myself when I read your comment. Could also use vom on millivolt setting.
It sounds so simple to have your battery in a heated environment. Those of us who have remote cabins in cold weather areas and don't live in the structure, that is not so easy or should I say.........impossible. This is presently being addressed by the leading commercial battery manufacturers and I expect within a year this will become practically a non-issue. However, this issue kept me from going LiFePO when I bought new batteries for the cabin 15 months ago. The advancement of the technology surrounding this chemistry evolves so rapidly it is amazing.
I always used locktite when I competed in car audio 5 farad cap and 3 batteries with 2 150 amp alternators. Needed it or everything would come loose. Busted the front window and blow the sunroof out a few times
you gotta be kiddin me right? That's insanity!
Have you considered using spacers and using a fan to circulate air through the battery? Wouldn't batteries in the middle be most likely to get hotter than the outside due to insulation? A Simple PC fan could keep things cooler - or warmer depending on the setup..?
Sure. There is nothing wrong if you want to incorporate some form of cooling. Most electric vehicles have to do this since they are trying to push 300+ amps out of the cells. In my case I built this for small off grid stuff, like lights and mini-fridge. I just won't be pulling enough amps to create excess heat.
For Solar power application, what's the most optimal charging setup? Panel/charge controller/wiring.
Nice man great job!!!!
All fine, your builds are low voltage and amperage ones there this simply not matter. Good job, nice engineering. Electrons like to travel as close as possible to surface or even on the surface of conductor all depends on voltage and amperage. My apologies for non-professional wording but i tried to dumb it down for average as possible.
very nice video, gonna copy your process, including the locktite, sheesh!
The best thing for you contacts would be Humiseal. Don't use Locktide, torque the contacts correct and then apply a thin layer of Humiseal. Thats protect you contacts for corrosion and loosing. Its always used in the Aircraft Industry for the electrical connectors with thermal lugs. A added spring washer will help you to lock the screw.
Thank you so much for sharing your videos! I don't know if someone already posted this question, can lithium battery to be built as a deep cycled one to be used in motorhome chassis battery? What need to be cared for? Thanks!
Yes, people have done that. However, I haven't because I don't own a motor home. I'm sorry I'm not going to be much help.
Too expensive. Marine batteries
It would be useful to know how many man hours you expended on this project. Obviously, subsequent battery builds would be faster. If someone were to build 4 to 8 batteries, an estimate could be made regarding total man hours, with an estimated efficiency increase in later builds. This provides a useful aid in deciding whether or not to build your own, or buy Battleborn. Victron, or other brand batteries. Some have more time than money. For some, the satisfaction of DIY is worth it both for knowledge and competence, even if buying would make more sense. For those less technically competent, buying is obviously the better option. Those choosing to watch these videos likely have higher competence in attempting DIY. Thank you for helping feed our technical curiosity.
I wouldn't mind building another as a speed test, but these builds get expensive. $440 in parts. I need to wait for the views, and next months ad revenue before buying more materials.
Great videos! Thanks bud...
Cool video. But at $477 for 1 battery? I understand that LiFePO4s are expensive. Last summer I used 1450 KWh in one month. I would need MANY of them to do what I need. Good luck with yours.
I noticed you didn't put Locktite in all the threads leaving part of the threads clean to conduct power. Since it doesn't cover all the threads I doubt conducting power in the threads will be a problem. Especially as you point out a lot of power can pass through directly from the side of the terminal. The only way I can see it could possibly make a difference is with extremely high current loads.
I was taught long ago a little goes a long way.
Low Temp is all because Will P, I bet!
Nice! Currently building an approximately 100AH lithium for a trolling motor, I can't see spending $900+ for a dang battery! But for less weight and FAR less cost (half the size of your battery) I can DOUBLE my water time! Certainly blows away using 18650 batteries!!
i luv ur lids... ty
i was wondering ... could ur build be stackable in both parallel or series configuration..?
... where did u source ur case..?
... How long dose it take to charge from cut off to full charge..?
... would this be safe to keep in my home full time? its cold here...
Yes, you can series and parallel them. I bought the case from Aliexpress. It can be charged in 2 hours (faster without the circuit breaker). It is one of the safest lithium chemistries. However, I still recommend storing batteries in an out-building (shed or garage).
I've had a concern for some time as to whether a battery system can heat itself from power from the batteries to keep from low temperature concerns. (When in an insulated compartment, of course!) Then, does the increased battery efficiency from self-heating translate to a net gain or a net loss of battery capacity?
The military uses this T.O. 1-1a-14 for electrical practices its about 1300pgs i think happy reading
Hello, where did you order the battery box from? I did not see a link posted.
I wondered that too -he said it was Ali-Express but a search for "Battery Box" doesn't narrow things down very much.
The only problem i see with the lock tight would be i would put it into the hole rather then on the stud... that way if there is any "extra" lock tight it would be pushed into the connection rather then building up at the top maybe building a small film between the brass and your ring connection
Nice build! Why did you choose 12V? For what application are you going to use the battery for?
I was asked thousands (yes, literally) to show how to make a 12v battery. I assume those thousands of people have some application in mind.
@@DavidPozEnergy RV off-grid camping is probably the biggest driver, since everything factory is 12V it's pretty expensive to convert to 24 or 48V. I looked into using DC-DC converters because you can get used 48V packs pretty inexpensively but a converter that can handle the 60A charging current from the converter is not cheap, especially if it has to be outdoor rated.
David, being it over a year since this video, would you build or purchase? IE rack mount battery vs building your own rackmount battery?
No, for $100 more than I spent in parts you can buy a pre-built battery. Lots of great options have come on the market this past year. Personally, I'd get this one: shop.signaturesolar.us/products/12v-100ah-lifepo4-battery-by-eg4?ref=4_rHcgZ9x-TiF-
@@DavidPozEnergy thank you.. I have 6 pros on order with signature :) I am liking the configuration.. stay warm and safe.
Thanks for sharing .
In a car camping application, would it be possible to charge this battery from the vehicle's alternator, by connecting it to a 12v cigarette lighter?
The short answer is yes. But, there is a risk of blowing the fuse on your cigarette lighter because if the lithium battery is low, like 12v, and your alternator puts out 14v, then it might draw high amps. And if you connect it directly to the alternator, you may burn out the alternator.
A safer way to charge is to use a 12v-12v charger. Like this one: amzn.to/3hCZ423 (affiliate link)
Can you give us a link on the compression wire tool? thanks
I really liked this video.
Now I'm curious if anyone has built this for high power draw use and designed active cooling. I'm tempted to use this design for an EV and design the system for easy swap out of batteries instead of charging in situ. Nobody is doing this commercially, which leaves me wondering if the logistics of swapping out batteries is not worth the effort.
By the time you've built a battery (even a LiPO battery) for a decent range, you are looking at a fairly hefty (got an engine hoist handy? heavy) battery. I've seen plans for such things, but they always cite the weight of the battery and the challenge of making a high capacity quick connect as the big failings.
I think if you put the loctite on the bolt it could run out/squish and coat the surface of the brass part that is in your circuit, potentially not great. Solution, just put the loctite on the inside screw thread (not the bolt), and not have so much that it would squish out. Then the brass surface stays clean!
Hello. Is the lithium battery charger like opus if it works for a long period of continuous days affect its work or not
After the low temperature shutdown what steps did you have to do to re-enable the batteries ability to be discharged?
Nothing, it will still discharge below freezing, just not charge.
Thank you Mr David pause for your excellent content. I'm looking to find out more about the battery box you have? I looked over on 18615 Ed and did not see any there period could you give more detail on the Alley Express information such as a link company name or anything else I can lead us to finding it thank you
If you message Keith, at 18650'ed, he has them and can ship it out, he just doesn't have them listed yet. But the one I bought on Aliexpress: www.aliexpress.com/item/33030465274.html?spm=a2g0o.productlist.0.0.30436455ktYQrF&algo_pvid=139964d4-2b71-461d-a3a1-ac25f5cc9a8a&algo_expid=139964d4-2b71-461d-a3a1-ac25f5cc9a8a-2&btsid=0bb0623416030517225768406e4b30&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
In regards to not wanting the bolt to come out, and with how "built to last" you've done everythying... .once you are happy and ready to close it up for good.. they make conductive epoxy... you could use that rather than threadlock
on the nickle test just use a dremel tool grinder if no sparks then no steel
To me, the number 1 question is what’s the total cost (products & tools) required for complete assembly?
I'm not sure you fixed the potential short issue with the card under the positive end. The nickel was bent over the edge of the cells so at the very edge it could still rub through the shrink wrap. Your insulation should have gone around the edge of the cells.
The ends of the cells are protected by the plastic cell holders...
I agree with you on the loctight!
I don't have a welder to put them on would it be okay for soldering iron
Some people do, but I don't because you have to be super fast with your soldering skills not to over-heat the cell. I'm not very good at soldering, so I bought the spot welder.
Is nickel ferromagnetic, or could you use a magnet to determine if it’s nickel plated steel? Wouldn’t nickel plated copper be best?
I don't know about the magnet. But for copper... I have a coil of nickel plated copper and tried to get it to stick, but couldn't. Not sure what kind of high-tech welders are used for it, but not my hobby spot welder.
Ah, I wondered if spot welding the copper might be the problem. Now I know! ;)
Nickel is one of only four metals that are ferromagnetic, meaning they are attracted to magnets and are magnetic themselves. The others are iron, cobalt and gadolinium.
Could you explain how do you charge you battery ? I saw your Mean Well Model RSP power supply. Do you use any buck or boost with CC/CV converter in between ?
Yes, I have a variety of different buck and boost converters depending on what I'm doing. For this I was using my ISDT Q8, which is a hobby charger, and the 24v power supply.
@@DavidPozEnergy Cool, Thanks for your explanation.