yeah mate. a lot easier to handle a chain with 6 links than a double sided chain of 12 links. makes installing (and uninstalling) the battery a lot easier
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Hmm, thatâs a good idea. My intention was to join them with a couple wraps of fiber tape and some craft foam, but if Iâm already using 3D printed parts, I could totally just make some custom pieces to let me glue them together as well.
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yeah I usually glue up both groups with the separators and then fishpaper/tape the entire double group. makes it nice and neat.
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I like your suggestion, it looks a fair bit nicer than two separate packs.
Not sure if you can tell from the picture, but the spacer things that separate the two p packs are about 1.5mm wider than the other ones, giving the middle cells there some air gap between them. In this one I filled the gap with glue, but I think in other packs Iâll throw in a strip of fishpaper before I glue it up. The cells donât touch at all, but it doesnât hurt to overbuild a bit.
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I get why you did it that way but damn, thatâs ugly as hell. 
Good thing it wonât be visible form the outside.
Yeah the gaps are very visually unappealing, if my enclosure was about 3mm taller I could have stacked them nicelyâŚ
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Hey I just finished my 12s4p battery. I was looking for recommendations about the correct AWG of wire to use coming from Batt main negative and positive. Aslo does anybody have a wiring diagram to show the correct order to wire in the Battery to the BMS, Antispark/power button, Charge port and ESC? Like the correct order on Negative or Positive. Any thing would help. Thanks!
For starters, post some pics of your battery build for some feedback as this seems to be your first attempt.
Re BMS wiring, typically the below diagram will work for most BMSâs with common port but it could be different based on what brand youâre using. This is wire for âcharge onlyâ where you have bypassed the BMS for discharge and is, generally speaking, the preferred method for Esk8 batteries. There is also a loopkey wired in here in place of anti-spark which will serve much the same purpose and will also act as a circuit breaker. If youâre using something along the lines of an antispark switch seperate from the one included with your ESC, this diagram does not outline that wiring arrangement.
In terms of order of operations when completing your battery, that will differ for some people. Personally, I complete all the series connections, then wire the main battery leads with the loop key wired into the neg lead. If you arenât immediately terminating the leads with an XT90S, then shrink tube the ends to ensure there is no chance of a short. Then, wire your BMS leads as above. Then, before plugging the wiring harness into the BMS, check your voltages on the harness. Start w B0 and work your way across. The voltages should increase with each lead depending on your SOC (e.g. B0â>B1= 3.5v; B0â>B2 = 7.0v and so on).
Once all of this is done, test your charge/discharge to make sure everything is working. Then, shrink wrap (etcâŚ) your battery.
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suggestions for an 18s bms?
I usually use JBD or Daly BMSs over 12S. I did not shop around with these links so you should search more for a better deal.
https://www.aliexpress.com/item/1005004677735278.html?spm=a2g0o.productlist.main.3.66c57978Yktp8k&algo_pvid=f4d37a30-ba03-4e00-817d-e9f7fb148843&algo_exp_id=f4d37a30-ba03-4e00-817d-e9f7fb148843-1&pdp_npi=3%40dis!GBP!52.92!37.04!!!!!%40211bea0816860594248206555d07b9!12000030072735821!sea!UK!949050806&curPageLogUid=djfbRuUqn6rn
https://www.aliexpress.com/item/4001327098788.html?spm=a2g0o.productlist.main.5.1ccc713biJrZqY&algo_pvid=8f510498-804e-439a-8b43-b4b0fa1673a8&algo_exp_id=8f510498-804e-439a-8b43-b4b0fa1673a8-2&pdp_npi=3%40dis!GBP!62.98!40.31!!!!!%40211bf2da16860594909954314d0787!12000025114157234!sea!UK!949050806&curPageLogUid=VFdiPhFtbPM4
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How do I know if my welds are good or bad. First time welding batteries.
The positive side was done at 25ms and the negative was 15-20ms for reference.
Well, for starters, you should have fish paper rings on all the pos terminals of your batteries.
If you search this thread with the key words âpull testâ youâll likely get some hits.
These batteries have 2 insulators on them and they are just for testing. They will not be going in the board, but ok I will look up the pull test, thanks!
They appear to be made of plastic⌠are my eyes deceiving me?
When any cell hits âovervoltageâ (4.25 in your image) the BMS will cut charging.
It will prevent charging until the cell is below âovervoltage releaseâ
so if raising overvoltage release from 4.15 to 4.20 did the trick. at least one cell was getting pushed to 4.25 and stopped charge, cycled back to 4.20 to let the charge keep going, probably cycling like that.
Iâm assuming youâve checked the voltage at the charger⌠I canât see any settings that would be preventing you from a full charge.
@Battery_Mooch @MysticalDork @glyphiks
Any help here?
2nd that. often the cause of these symptoms.
oh no they are both plastic. I just didnt think it mattered if I wasnât actually planning on using them. I will put fishpaper on them now.
No if youâre not using them itâs less important but if youâre connecting live cells in parallel, you should really always use them.
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