Revisiting DIY Li-Ion Battery Packs // Sequre SQ-SW1 Spot Welder // Samsung 30T 21700
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- Опубликовано: 29 авг 2024
- DISCLAIMER - lithium batteries are very dangerous if mistreated, take it slow & do plenty of research before working with them!
Last year's video - • DIY Li-Ion Battery Pac...
3D printed jig for 30x10x0.2mm nickel strips - www.thingivers...
I am using the Sequre SQ-SW1 spot welder, powered by a Turnigy Rapid 5500mAh 3S2P 140C hardcase lipo. I have no affiliation with either company.
Cells I'm welding are Samsung INR21700-30T - lygte-info.dk/...
Music -
Philanthrope, Sleepy Fish - Away With the Fairies pt. 2 chll.to/34bbb9f1
Really nice soldering job 👍
I found this positively enthralling, nothing negative to say. Watt will you come up with next?
I want to hate you, but I just can’t 🙃
What tape are you using to wrap the battery after building?
That’s just regular PVC electrical tape, my preferred brand is Tickitape
Dear sir love your work. Did you chack the c rate of the pack?
These cells are rated 35A which would make the packs just over 10C. Look at lygte-info.dk for tests of cells & their current claims.
Great job!
Hi CJ.. Great video and I've subbed 👍 I've just purchased the Albabird and going to power via li-lon.. any reason why your double packing? Off subject but what's the Albabird AUW using those packs cheers.
I'm using 8 cells simply because that's what physically fits & balances on the CG easily! In terms of current handling, a single 4 cell pack with these sort of cells is probably plenty as long as you're not pegging 100% throttle the whole time. I actually don't know what my Albabird weighs, but I can tell you each of these packs is just under 300g. I will happily admit these particular cells aren't the ideal choice (you can get 18650 cells with the same capacity & current rating now) but I got a decent wholesale price on them.
Cool thanks for the reply 👍 yes I was thinking about 600g of battery's should be ideal.. I'm looking for over one hour flight time cruising at 5A ish I hope lol stock motors props etc.. cheers.
Do you find that your choice of nickel strip (0.2mm thick x 10mm wide) has sufficient ampacity for your needs? I've read it has a rating of 7.9A and I wasn't sure if flying a drone would exceed that since I thought some punchouts/accelerations can regularly exceed 30A? Thanks for any clarification you can provide!
Current is so scenario dependent there's really no useful way to say that a particular dimension of strip has a specific 'rating'. The same is also true of wire gauges of course, but because people are more familiar with AWG it's easier to understand the 'real world' capabilities rather than taking the textbook tables as hard 'limits' that can never be exceeded. According to some textbooks, a 14AWG copper wire can only handle 5.9A, which in certain scenarios may well be true. But in the scenario of a 5" race quad screaming around for 4 minutes pulling >100A bursts, that 5.9A textbook rating is meaningless.
I recommend reading through some of the (extensive!) discussions & tests on Endless Sphere, Esk8 News, etc. to get a better picture, particularly those that try to compare different dimensions of strip to roughly equivalent AWG of wire. Many people consider 0.2x10mm pure nickel to be roughly equivalent to 15AWG, which seems ample for my purposes.
@@CJDavies Yes that makes a lot of sense! Sometimes all this reading and planning can make it easy to lose the big picture! Thanks so much for the help
I have one huge issue with this comparison. You are correct, .2mm×10mm =2sq mm which is equivalent to a 15 AWG wire. Problem, I've seen nickel wire. .2×10mm wire is good for a CDR of 7.9A. A copper wire that can carry that current is a 20 gauge wire which carries 8.2 A. A 15 AWG, can handle 25A. You would have to have 3 layers...or, which I have done, is solder copper wire to increase thrurate. A 18 gauge bare solid copper wire can carry 25A
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I plan on using molicel p42a cells to make some 6s1p packs. I’m struggling to find useful info on the strip size. What do you suggest I use for a 45A max draw?
I would recommend reading through some of the discussions & tests on Endless Sphere, Esk8 News, etc. that try to compare different dimensions of nickel strip to different AWG of wire, rather than looking at the tables of hard 'limits' copied from engineering textbooks. The problem with the textbook figures is that they don't usually take dynamic load/duty cycle into account. Some textbooks will tell you that 14AWG copper wire can only handle 5.9A, but we know full well from our real world experience that at least in our RC applications that is a meaningless figure. Many people consider 0.2x10mm pure nickel to be roughly equivalent to 15AWG.
The NEC ( National Electrical Code) rates 15 awg copper at 24A. Never ever saw a rating like that. .2×10mm is going be holy short of 30. If he is banging 30 amps out fairly often, wo
012523/0414h PST 🇺🇸 Thanks for the link.