48v DIY Battery in an Ammo Can

This build is a 1.3 kwh battery inside an ammo can at 48 volts!
I'm using 168 lithium cells. These cells are called "18650" for the size. Each cell is rated for 3.6v and 2200 mah. This means each cell is about 7.92 watt hours of capacity. When we add them all together this ammo can contains about 1.3 kwh (kilo watt hours). I arranged the cells in a 12p14s for a nice 48 volt battery.
Inside the ammo can I included a 20 amp circuit breaker and a 60 amp BMS. This provides protection built right into the enclosure. By using a real military metal ammo can, we have fire protection.
I used a 20 amp circuit breaker to limit the discharge. This is in an effort to keep the heat from building up. However, the charge current should be half of this.
Thank you to HBPowerwalls KZbin Channel: kzbin.info
K-weld is sold by 18650ed, Keith is the owner. 18650shrinkandcellholders.com/kweld/?fbclid=IwAR31sKwkz9pi7WjJ2YMQQSjnNOo60CzxghahmdyS1Jv59NR0pfcaLHY2YpI
18650ed Ebay Store: www.ebay.com/str/18650shrinkandcellholders
The ammo can came with the positive and negative posts already installed by Battery Hookup. I also used the nickel fuse strips from battery hookup. When buying from Battery Hookup please use my coupon code "davidpoz" for 10% off your orders. This also tracks the affiliate program, which helps out this channel. Thank you.
If you would like to help support the channel, you can do so through the affiliate links below, and/or through Patreon. Thank you. www.patreon.com/DavidPoz
Battery Hookup affiliate links:
Modem Packs: batteryhookup.com/products/4-18650-2200mah-cells-in-modem-batteries?rfsn=3333666.ca06e9
Ryobi Packs: batteryhookup.com/collections/green-friday-weekend-deals/products/ryobi-op4026v-36v-batteries-for-parts-repair?rfsn=3333666.ca06e9
Nickel Fuse Strips: batteryhookup.com/collections/cell-level-nickel-fuse/products/nickel-fuse-2p-wide-continuous-roll-by-the-foot-18650-cell-level-fusing?rfsn=3333666.ca06e9
Amazon affiliate links:
ISDT Cell Checker: amzn.to/3cV7Upa
JST-XH Connectors: amzn.to/2w0QSVX
Solder Iron: amzn.to/38OtzMm
Flux: amzn.to/2TWsHjo
Solder: amzn.to/2W4p6T7
Aliexpress Affiliate Link:
Daly BMS: s.click.aliexpress.com/e/_d6XCdHf
“As an Amazon Associate I earn from qualifying purchases.”

[@Helamanize]

I am building my own off grid solar system and have been watching youtude videos now for about a year, which sort of makes me an expert viewer, you and two other individuals produce some of the best video, steady camera, good explanation, and no "Ahs" every second word, thanks for your hard work trying to help us new users to solar....it is much appreciated

[@saadomar1101]

I am wondering if packs like these can be cycled everyday to some percentage (not full) or if they are for backup purposes only,

[@simplyengineering2350]

@@saadomar1101 If they're charged to 4v per cell and discharged to 3.1v per cell then the maximum cycles will nearly double. Charging them to 4.2v and discharging them lower than 3v is the standard. The last 0.2v is about 200mah, or lower depending on the cell's max capacity. So not much trade off to gain a lot more cycles.

[@Mad-Coo]

Man this is awesome !! Discovered these 18650 by accident recently and for some strange reason i am following online and buying tons of gadgets, chargers, cables, multimeter, etc, etc, building a battery pack myself, i first got cells from my old Thinkpad, testing them was fun and i fell into the rabbit hole so to speak, i am autistic and this sort of thing is right up my street, always enjoyed having collections of batteries and chargers but never had a need for 18650 until now, its so addictive !! great video thanks.

[@andrewriley1664]

Hi, been watching your channel from the UK for ages and to start with had no idea about batteries/solar but after a while of watching I now have a basic grasp of the theory.. Many thanks and hope you continue to post vlogs to us newbies😊

[@DavidPozEnergy]

Glad to help. I'm new to these small cells (18650). This was my first build with them.

[@NikkyKnowsUNzs2001]

Being able to make your own power supply for different voltage/current levels today is more important than ever!!When you have your own electrical power at any level whenever and whereever that can be applied as quickly, safely is "SUCH a powerful tool to have!!!!!!!!!!!!!!!!!!!!!!!!!!

[@kennethalmond8922]

Careful - 18650(s) are addictive... I started with 96 of them and 2 years later they grew to 1,000(s) :) You may have done this but you didn't mention it, so just in case, let me suggest that one should match the ah(s) in each parallel row so they all have aproximately the same ah. For example, 12 * 2300ah cells in 1 parallel row is 27,600ah so you you want all the other parallel rows to have aprox 27,600ah total (+ / - 5'ish%). The better they are matched, the easier they will stay in balance as the battery is charged/discharged.

[@DavidPozEnergy]

LOL. I can see how addicting they are. Very satisfying.

[@RodneySolarCircuits]

yes same story here. now I have over 4200 cells 14s300p

[@Musicpins]

I can see how important this is Kenneth, I guess it matters more the more cells you have in P? Anyway, I'm considering making my next build with those 26650 LiFePo4 for my workshop powerwall (3kwh) The problem is I can't find a charger/discharger for those that can do the Milli-ah calculation. I don't think my Xtar Dragon 4 thingy can do that chemistry, even though its a GREAT charger.

[@lasersbee]

Thank for sharing and the parts list\costs David. You're getting a lot better at builds...;-) Well Done.

[@DavidPozEnergy]

Thanks for watching.

[@JAC13]

I have been using those modem packs for about 6 years now and have never been disappointed.

[@ahmadfaiq85]

That coil whine of the spot welder sounds so cool

[@Energizer34]

I love that spot welder!

[@worldwide_wes]

Your spot welder is the most satisfying sound I've ever heard. It should be the default sound on all computers for "your input was successful".

[@Bepnm]

David wearing safety glasses. Norm Abram approves.

[@ronaldharris6569]

That spot welder is amazing

[@Musicpins]

It is totally freaking awesome, its the best tool I have ever owned. Its available from Keith as David says, but if you are based in europe just go to www.keenlab.de/index.php/product/kweld-complete-kit/

[@GoingOffGrid101]

i made one of those a few years ago, same ammo can. I used lipos in mine though and glued a 300w inverter to the side :D. Loved the build!

[@DavidPozEnergy]

I seem to remember you taking apart Ryobi packs for the Lipo cells. Is that a related build?

[@GoingOffGrid101]

@@DavidPozEnergy I used RC lipos in mine.

[@trevinom69]

Great video. A couple of things I noticed. You mentioned that you set up the jst connectors to hook up your little gizmo to see how your batteries are doing....in reality it will only show you how each 'group' of 12 batteries, set up in parallel, are doing. It will not tell you if an individual cell is having issues. This will initially be masked by having the others cover for it, forcing them to work harder and weakening them as well. Which can lead to issues down the road. Unless you check them individually, you can only check up on the group as a whole. The 2nd thing you mentioned is that you don't have to make all your batteries at the same time, that you can add to them as you go along. This might not be a good idea unless you can match their capacity. For the same reason as above, if the first battery you put together was in good shape, a few months later, after alot of use, it might have lost some of its capacity. If you then put a new battery together and add it to it, it will potentially be at a different (higher) capacity. This will lead to it working harder to cover for the older battery which will lead to it's losing capacity earlier. The stress could also cause the individual batteries to get out of balance and because you can't check them individually... You ideally want to match battery amperage and capacity before pairing them.

[@ProlificInvention]

Probably the nicest Electric Bike DIY battery pack I've ever seen, very nice work! Making one immediately for my bike, probably use a plastic ammo can and put it in a backpack with a pigtail quick connect for security and stealth

[@DavidPozEnergy]

That will be great for an ebike.

[@zilog357]

Great video, great build. Thank you for sharing and disclosing the sources.

[@N8TheSnake]

Betting this is super doable and easier with prismatic cells as well! Nice video Dave!

[@DavidPozEnergy]

I'd love to build it with some prismatic cells.

[@N8TheSnake]

@@DavidPozEnergy Pretty sure the prismatic cells would cost way more though. You got out pretty cheap on this one!

[@freakygardener8033]

The technical jargon is WAY beyond my brain capacity, but still a very cool build vid!

[@ericmcginnis9413]

Something I wish I was good at! I love building car systems and E bikes so I can see having a use for these!

[@ancienttechnology7337]

This is by no means my favorite build I've seen you do but it gave me the gumption to try an 18650 build. Battery hookup posted some used salvage valence batteries which as you probably know are full of 1300mah lifemgpo4 18650 cells. I got 3 batteries in the pack but there's bad cells in the bunch, so I'm hoping to get 200 good ones out of the 300 cells. Not the most energy dense chemistry ever but tolerant, reliable and long life. We'll see if that holds up after they got used and abused in their past life. Thanks for the inspiration.

[@iflnr978]

thanks for the great video! i really like the 48v, size, cost, spot weld tech and value of this build.

[@DavidPozEnergy]

Thanks for watching.

[@PipeManPeep]

That spot welder is the business, isn't it?! As always, great work David.

[@DavidPozEnergy]

It's pretty good. Let me know if you think I should make a video on it.

[@PipeManPeep]

@@DavidPozEnergy No, I think you should give it to me to make a video on 😉 Seriously though, leave that to the manufacturer. I was building one of my own, but that one looks so good I think I'll buy one. Who did you say made it?

[@DavidPozEnergy]

LOL. I don't know who makes it. But Keith sells it through his company 18650ed. 18650shrinkandcellholders.com/kweld/

[@howiegrapek]

@@DavidPozEnergy Yes, make a video on how to best built it from the parts. intersting gizmo indeed.

[@rickybailey7123]

Great video thanks for your time ser !!!!

[@ronsafranic5177]

In my experience the red ones are always the ones that give me problems so I agree with your strategy of not using them if possible.

[@ZebbMassiv]

There's cheaper options for brand new all one brand cells instead of salvaging just gotta know where to look

[@kipdennis3796]

Thanks David, please do another video of this kind,respect from Kenya! Edit,am addicted to 1860 battery build but nowhere to be found in this part of the world

[@cfeigel]

That's a great little project! People will be able to follow along. Hey, on your miter saw, have you considered powering it with DC? It's probably got a "universal" motor that will run on either DC or AC. You'd need a 120 V pack, but you wouldn't need an inverter. Keep the projects coming!

[@DavidPozEnergy]

Do you know of any blogs or videos where someone has done it. I don't want to experiment with such an expensive tool.

[@lenturnbow6417]

You’d need a beefy external power switch. D.C. arcing can destroy an AC power switch in short order. (See what I did there?)

[@jimthvac100]

Very nice neat job. I love that welder you're using.

[@adriancoleman2876]

i love finding those LG's in laptop batteries. they are so dependable.

[@blindsay]

Thanks for the video, been looking into building a DIY eBike and building my own battery pack for that so I have been watching just about everything I can using 18650 cells haha.

[@ronsafranic5177]

David there is a plastic sheet called Coroplast that is like plastic cardboard. It is commonly used to make signs and you can get it for free from some gas stations when they throw their signs away. I prefer to purchase 4X8 sheets and cut it up to make my dividers and covers. I use Kaptom tape where appropriate but only use packing tape on the Coroplast because the Coroplast in not high temp so why use high temp tape. Your plastic bottle is also not high temp but the Coroplast is much easier to use. Coroplast comes in different thicknesses the 4mil is the easiest to find and is what most gas station signs are made of. I much prefer the 2mil type but you will need to go to sign store to buy it!

[@sunshine5349]

cool little monitors!! thanks for the education

[@Gabriel2.0]

such a nice build

[@MiniLuv-1984]

Nice package David! Great value option too.

[@adambatchelder4121]

Pretty clean build. I guess I would hard mount that breaker to the lid of side of the box but that is just me.

[@Newman81964]

I used an ammo can to make a self contained tester for checking trailer lights and trailer brakes. It only had to be 12 volt to operate the lights or brakes. I use it to test to trouble shoot if there is a problem or after doing a repair on any of these circuits. To charge it, I added a 12 volt power socket on the outside that I can connect to the 12 volt socket on my vehicle while I am driving. The socket on the ammo can can also be used to operate anything that can be plugged into the 12 accessory socket. It has the digital display that shows the voltage and also shows the current amp usage of whatever it is operating. The amp readout is great for testing the trailer brakes. By looking at the amp readout, you can tell if one of the brake electromagnets is bad or not.

[@DavidPozEnergy]

That sounds like a perfect application. Thanks for sharing.

[@onensoneens5689]

I've also some bad luck with the red Sanyo sells, they are really hot when i use them and i had some old ones in the past that had leaked, no other brand that i've personally seen had done that

[@jarekmace1536]

For padding, I would suggest either a 5mm craft foam or the anti-fatigue mat available from Home Depot. It will not likely break down, unlike bubble wrap, and can be better cut to shape.

[@DavidPozEnergy]

Thanks. I'll check it out.

[@fisherus]

Wow Bud, you lost me watching your disassembly of the battery packs. I was figuring out how long it takes just to dress the batteries up and testing them. You work like a robotic machine. It would take me about a year per battery. I figured I would never have a battery bank built large enough for my needs before I died. Sure enjoyed watching your build.

[@DavidPozEnergy]

The first pack took me an hour (4 cells) but I very quickly found the groove. At the very end I even had it down to 32 minutes. I posted 40 as a good average.

[@chbaisla]

If you are a good engineer I wish I was born in America and would have come to you and taken a lot of knowledge.

[@CaptSalty1965]

Dave, loved the video. I live in Woonsocket and not far from 18650 Heat Shrink & Cell in Lincoln. Sounds like you are not too far away either. Would love to grab a coffee sometime. I have a slide in truck camper that I want to put 200-300 watt panels on and a couple of Lifepo4 batteries so I can boondock for a week or two off grid without starting the generator.

[@DavidPozEnergy]

Sounds like a great project. Can you contact me through Facebook? facebook.com/DavidPozEnergy/

[@GapRecordingsNamibia]

Hi David, once again awesome video! A few things, you need to sort the cells into banks capacity wise , the reason being when drawing current from the pack if one P has a lower capacity it will drain faster than the others, thereby causing the pack to discharge faster than it otherwise would have. There is an online cell logger I think on battery hookups site? Not completely sure on that one so don't quote me there, Average Joe uses it when building his batteries to closely balance his P's capacity wise. The other thing I would have done before heat-shrinking the battery would have been to charge it up and do a full few cycles drawing enough current so that you could monitor the cells with a thermometer or if you have one an IR thermometer so that you could see if there were any problematic cells before sealing everything up. It would suck big time to have to tear it all down just because of three or four cells not wanting to play nicely together. There are a few downsides to using recycled cells, BUT, it sure beats the crap out of a LA battery, AND! You DIYed IT! Once again, Awesome build.

[@DavidPozEnergy]

I agree. The website is repackr. You put in all the cell capacities and it organizes them for you. I wanted to do this, but couldn't. The tester I used was way out of whack. I couldn't trust any of the numbers it was giving me. If I had used some Opus testers, then I could have trusted the numbers and I would have used repackr. that was my original intent. The only good thing about the tester I used was that it charged and discharged the cells heavily so I was able to see if there were any "heaters". (none). I plan to do a follow up video with some testing. I'll let you in on it. I discharged the whole thing in under 2 hours, (high amps) and we did not exceed the cells data sheet for maximum temperature.

[@startcherif]

Very nice video,good job

[@ranger175a2w]

Nice job David!!

[@askostadinov]

Brilliantly designed pack! I've would add third wire to buss bars. Do not leave these voltage monitors / ballancers unattended in the pack. From what I remembered they drow their supply only from one cell in the pack. If the pack is left for long time without charging, this cell will be drained. Keep the good work

[@DavidPozEnergy]

Thank you. Yes, that's correct about the cell checkers.

[@shawnd567]

I've been thinking about doing this with my ammo cans!! Thank you!!!

[@ricininepartypillz9248]

That's exactly what I use except with a IEC/UPS kettle connection,I can't guarantee that mine are water proof but it's an innie connection so water will have trouble getting in

[@Matt-wb7lm]

Great build. I have 2 packs almost identical to yours. I use them to power my tandem trike. I used Samsung CGR18650DA cells and can pull 40A without any problems. I wish my packs looked as good as yours. Thanks for a good video.

[@velojoy]

love the spot welding

[@frankz1125]

Great video

[@donnaperry1654]

Very professional.

[@jehugarcia]

awesome!

[@DavidPozEnergy]

Thanks Jehu. I really appreciate that coming from you.

[@jayclark8271]

Sure! It’s easy to teach something if the audience already knows all your ackronyms! That’s like teaching into the mirror. Only needs one person, no empathy and no thinking. Bye.

[@jfh400]

@@jayclark8271 this comment is a POS

[@BillyAlvarenga]

Nice I was waiting for you to start with 18650 cells. And yes I want to see a high amp 18650 cell pack or 21700 cells. Keep up the good work David. Greetings from Spain :)

[@stevehastie6032]

Yep I want to see you build it for your chop saw cause I want to do the same thing thanks for the vid

[@ehababdulburalfakhory801]

Very Nice

[@BenBuildsDIY]

Nice build! Best practice would be to crimp and solder the connection from your bussbar to the BMS.

[@DavidPozEnergy]

I don't know which is best, crimp only, or crimp and solder. But I do know that no matter which way I do it, there will be people telling me to do it the other way. LOL. When I made my video on LTO I crimped and soldered and received quite a bit of negative feedback for that.

[@BenBuildsDIY]

DavidPoz Haha, I made a video with crimp and solder and received similar feedback. One of my electrical engineering profs justified the crimp and solder method stating that the solder wetting the copper prevents copper oxide from forming at the junction. Copper oxide is significantly less conducive than copper metal. Additionally the solder helps prevent the connection from wiggling loose as the crushed copper deforms over time from the pressure causing the connection to loosen up. Just my 0.02- I’ve never had trouble with crimp and solder and have seen crimp only fail many times before (mostly due to bad crimp jobs though).

[@DavidPozEnergy]

Thanks for your 0.02. I like your explanation, make a lot of sense.

[@thenuts133]

Hey Dave if you see this. You have to go to harbor freight and get a pair of icon flush cut s. There expensive at $40 but lifetime warranty. I use them to cut the nickel off the cells. I did over 500 cells with my set. And they still cut like new.

[@DavidPozEnergy]

Thanks for the tip

[@neikesd]

skucome they used to say in the old days good job dude

[@sidhelo5206]

Wow You are a good teacher

[@lennyrossa834]

that would make a savage battery for my 48v 750w ebike and id love to do a build like that,but id be nervous as hell that id mess it up

[@kymflowers6644]

Great job, very knowledgeable

[@davidjames1684]

Decent, except for the low amperage. Much of the fun of using that size battery is being able to draw hundreds of amps out of them when needed. I use only 6 of the 18650s in a portable "juicer" for my smartphone and it works well. I just used a "hodge podge" of batteries, some new, some used, I didn't care. It can charge my smartphone 3 times from 0 to 100% before it needs to be charged too.

[@grahamswain7356]

Very good video. And interesting of course useful.

[@jaksilver3656]

that leftover nickle scrap would be great for electroplating

[@Todd_G_FPV]

What a nice build! I'm still trying to convince my wife to let me build one but she says I've already made to many battery fires haha

[@williamcrowson7755]

I got a hundred of those packs last month. Still working on the damn things.

[@DavidPozEnergy]

Me too. I bought more during that big sale and am working on them.

[@reggiejewett7591]

you could use them for a Golf Cart 48v times 4 of them would give you over 5 kwh . You would need to put at least a 400 watt controller I think. If you went easy you could probably go 3 rounds of golf before a re-charge.

[@mr.c6932]

Would 2 be enough to just drive around the neighborhood? I'm restoring an old EZGO Limo and want to drop weight and charging from the lead batteries

[@胡云庆]

Specializing in manufacturing 48v36v golf car lithium iron phosphate battery pack

[@michaelsims4475]

Hi Dave, just watched this video of yours and liked it a lot. I was a little concerned when I saw you wrap that tape and then the shrink wrap around the whole bundle. I know it looked nice and neat but I was concerned about ventilation and air cooling. At the end you mentioned removing the gasket, and I assume that was what that was for, but with all the tape and wrap, there is no way you can get any air cooling. Just my thoughts. Thanks for the videos. M.

[@dbeysoyt]

Heat dissipation is a concern for heavy loads or fast charges. Author mentions limiting the max amps for that reason. 20A max / 12P ~ 1.6A per 14S group, should not generate too much heat from 2.2Ah rated cells. For protection a BMS with thermal shutoff function could be used with sensors distributed within the block.

[@billk9628]

This would be a nice way too power up your RV camper. Small, and can be daisy chained in series for more amp hours. Imagine 6bof these in a camper, with solar panels on the roof, and a nice inverter. I imagine one could get several days off a bank of 6 of these.

[@jamest.5001]

I have 1400+ cells in a bank, 900-1000 are LG, the others are Samsung, all nos cells some close to 2900 mah

[@Dudleymiddleton]

Has to be the coolest idea for a battery yet! Looks like a 7.62 box? Remember though,(not teaching you to suck eggs of course) 48 volts does hurt a bit if you touch both terminals by mistake! :)

[@DavidPozEnergy]

It's painted, so I don't know what size rounds were originally in it. But it seems like a pretty standard size. About 6x11 and 7" tall.

[@gravelydon7072]

@@DavidPozEnergy Commonly known as .50 cal. ammo cans. Even though they are used for .30-06, 7.62x51, 5.56x45. A .30 cal. can is a smaller can( 7Hx10Lx3.5"W). There is also a "fat" 50 which is larger and again, is used for more than just the .50 cal. round, 8.75x12.5x7.25" .

[@ericmcginnis9413]

Great job bud !

[@danc2014]

You did not current test the battery. Thus you couldl have a unbalanced bank of batteries after a few use (think of one bad battery). This could lead to one of your banks becoming drained and reversed charged. That could lead to one large fire. does the bsm have a low voltage bank alarm or are the tabs also a fuse? What was this design based on?

[@DavidPozEnergy]

I have a previous video testing cells.

[@Mona_Lisa123]

20:24 That's a massive tip! "That's what she said"

[@seymourscagnetti1413]

WELL DONE! (BOTH THE BUILD AND THE VIDEO). LOOKS LIKE YOU BUILT A BATTLE BORN FOR SUB $200.

[@DavidPozEnergy]

Thank you. Battle born is using lifepo4 cells, so it's not quite a fair comparison, but I appreciate the compliment. As far as I know Battle Born does not have a 48v version, which would be nice.

[@andreykldjian]

I find it odd that Ryobi is using 15A cells. Most battery systems are using 20A cells and BMS. This just means that Ryobi battery packs are going to cut off sooner and wont reach as high a torque. Before you make a battery pack for your saw, test to see what the spike of current is at startup and also see what the current load is while cutting wood. I like your video. Keep them coming. :)

[@freddyfourfingerz9126]

1300 Watt hours? That's not bad for the price

[@Uisge4U]

Good project. What I would really like to see is a project building a 12V battery. I have a desire to replace the 12V house batteries in my RV and if I could build a reliable 12V battery to replace the deepcycle lead acids then that would be great. IF I could build a 12v 1.3kva battery for $200 as opposed to nearly $1000 for a battleborn then that would be a project I might dive into. Ideally it would be a drop in replacement for lead acid and be in that save basic form factor and ideally with top post terminals so all the current wiring works. A 24v or 48v just requires too much modification to the existing systems of the RV for me to really consider going that route.

[@PanelSuryaByGinanjar]

Whoaaaaa water bottle reuse for isolator... good idea hahaa

[@energycrafts8206]

Great build. Looks as good as factory made. Only concern I might have is with the ammo can is if there is any interior heat build up. How would you know before a cell goes thermal runaway? The can being fully enclosed would also not allow much ventilation of the packs. Maybe do a strong load test and show monitored temps at various cells IN the closed can and the outside metal of the can. Maybe the can is an adequate heat sink to air, but does not help if a cell becomes a heater. Great job!

[@DavidPozEnergy]

It's always about compromise. You can have wide open cells in the room, but no fire protection. This takes the approach of enclosing the cells to protect the room. The downside is you have to limit the amps to limit the heat buildup. That's why I used a 20 amp circuit breaker. The cells could do twice that. I have been doing a series of tests on it at different amps and measuring the heat buildup. It will be in a future video.

[@rhiantaylor3446]

Having measured the capacity of each cell, it would be sensible to allocate cells to each parallel group so that the groups all add up to the same capacity. There is a spreadsheet tool on the internet somewhere that does this for you.

[@DavidPozEnergy]

yes, the online tool is called repacker. I couldn't do that because the cell tester was very inaccurate, and inconsistent. I would have done that if I had some Opus testers.

[@martinlutherkingjr.5582]

I would drill some holes in the ammo can if you're going to keep the lid on. If the cells experience thermal runaway the extreme pressure inside a sealed metal container could be dangerous.

[@DavidPozEnergy]

The gasket is removed on purpose to allow venting and no pressure build-up.

[@shawnd567]

Please do a video with those high discharge Ryobi cells! I have a bunch and wondering how capable they are

[@sjcanalita3093]

Very very nice. Thanks.

[@burnzy56469]

If There was ever a major failure and the fuses had to blow. I'm not sure that plastic bottle would insulate against short circuits. I just watched the video that average Joe done with his thermal cam. Showing the fuses blowing. I would love to see that test. Love your vids mate

[@DavidPozEnergy]

Do you have any suggestions of something thin, non-conductive, with a higher temperature rating? I think 2-liter bottles are PET plastic, which is like 500°F. I think that's higher than the plastic in heat shrink, but I'm no engineer. There is also 2 layers of tape in the sandwich. I saw Average Joes video. It was great.

[@ThundarrZ]

Superb!

[@JKUadventures]

Is that spot welder really over $200? Unless I'm constantly making battery packs, that purchase would negate any saving of getting used cells. But awesome video!

[@DavidPozEnergy]

Yes, the spot welder is over $200. I hope to make more builds of different types, so I'll get some use from it. But if you only have one battery then there are other ways to do it without buying the spot welder.

[@JMerv80]

I thought the same about the price, so I made my own double pulse welder that provides consistent perfect welds for around $45. Check out 100A/40A Digital LCD Double Pulse Encoder Spot Welder Machine Time Control Module Board on ebay or Amazon.

[@robertmichael5024]

Thanks for sharing David. I was wondering if you would mind giving me the best lay out and component values that I would need in order to build a 220 to 240 volt 5 kilowatt off grid solar system? Themis.

[@lauchlingillis9255]

harbor frt sell plastic auto body tools which I use when I am dismantling lip packs. I believe it is a safer way to get salvaged batteries.

[@offgridwanabe]

Busy boy are ye lol looks nice and professional

[@DavidPozEnergy]

Thanks.

[@joepah51]

Dude you have a lot of patience! great job.

[@kerron_]

very cool

[@jamesdk5417]

Does it not matter that they are different max amp rated batteries?

[@RetiredPilot]

I would like to see how you charge this battery

[@codyparker5616]

Retired Snowbird solar ✌️

[@KentHenry8]

It seems like you have a great workshop and lots of tools. Were you building a different kind of projects before you got into the power walls and solar?

[@DavidPozEnergy]

I was a contractor, and energy auditor.

[@greg778123]

Not a bad idea

[@GrantArdern]

Great video. How would you make a car battery replacement?

[@stalwart56k]

Have you considered the Headway 38120 LiFePo4 batteries from batteryhookup for your Mitersaw? Maybe only in 24v for less weight. They are huge and their discharge rate is very high.

[@DavidPozEnergy]

Sure. Nothing wrong with those, the specs are great.

[@sunshine5349]

what is advantage of all this work to spot weld 168 cells together vs buying the big flat battery packs which are high amps/capacity and only having to solder in a dozen spots?

[@aspendell209]

Similar to some of my projects a few years ago. However no consideration was given to cooling in this design. There is a reason that Tesla builds their packs with coolant lines built in. A pack of this size will get quite warm when you try to draw/or charge more than 10 amps from it. Since yours is completely sealed from airflow to the case and insulated there is nowhere for that heat to go except into the cooler cells. Nothing destroys the life cycles of a cell faster than heat. Then once it gets hot enough you melt your petroleum based (plastic) divider between the packs and create a dead short throughout the pack. Small electric bike packs can get away with this type of design because the heatshrink wrap is directly exposed to the wind. But honestly, I'd be afraid to use your style of pack for any period of time.

[@haulngrassracing]

Aspendell Hench The reason is he is only limiting the power to 20 amps. 26 amps would roughly put you at 1C. So 20 amps would be a safe limit without fear of building any heat.

[@onlywenilaugh6589]

Wait until one or two or three or ...... of those batteries go bad. Lot to go through to find and fix. I've had quite a few failures of these 18650 batteries. Ryobi uses them.