That’s a good idea.
One thing though, it’s best practice not to have all the current go to one end of whatever your conductor is. So rather than soldering down a wire that comes off the top, it’s better to have the wire come from the middle. Or even better, have two (or more) wires, each spaced apart so they share the current. I’ll post a pic in a minute to show what I mean.
Where do you guys get 12s balance connectors from? Precrimped and wired.
Could buy a crimper and parts and learn but easier to buy if are they available economically.
NZ so shipping gonna kill me either way. AliExpress usually ok.
Doesn’t the BMS normally come with a balance wire harness with a matching connector and wires to solder to the battery?
No bms.
External balance charger.
I will use a different connection through enclosure (for waterproofing) to plug to the charger but want a splice between pack and that enclosure connection so I can remove pack easily if needed.
It’s just usually a jst ph (I think)13 pin connection with wires already on it. After pairs (M&F) really.
Edit. Found some from DRI.
Typical type for adding to battery. Just need one with the opposing connector.
You can also get pre-crimped wires and empty plugs, and stuff your own. I need to get a better crimper, mine is a piece of crap.
The male cables are usually crimped, and the female ones are usually soldered.
Cool. Maybe try that if I need to. Want easy option if it’s available. 
I recommend the Engineer pa-09, I get very consistent crimps with it and making wire harnesses much less of a pain.
I was looking at those, and also the IWISS IWS-3220M. Not a big priority, I don’t do connectors and harnesses that often.
Regarding crimpers, this is what I’ve gathered from the internet:
High quality (~40€$): Engineer PA-09
Good quality (~25€$): IWISS IWS-2820M
Avoid these (~10€$): Chinese clone SN-28B
Here’s a video comparing the first two:
The IWISS is good, I can’t complain. It works for Onewheel balance harnesses, which use a frustratingly small crimp and connector.
ahhh thats a great point! Those pictures did a fantastic job of describing things thanks!
Im fairly space constrained on the left and right sides as well as the front face. was hoping to keep the bulk of the wiring on the top face towards the front of the pack as shown by the first sketch below. I guess since I’m able to use smaller (maybe 10 or 12 gage wire) for the two short positive leads at either end that only carry 50A, I could do something like you suggest in the second sketch and still not have a huge bulge in the front of the pack like I would if ran 8awg.
I realize keeping the current path from each cell uniform is ideal but given the wire gages used here and the relatively short distance across the 4 cells, is going with sketch 1 vs sketch 2 really that big of a difference? I guess there is some fairly substantial current running through these connections (50A) but I really have no concepts for how unbalanced this would make the pack.
I also threw in some pics of the mounting constraints for the two applications I’m using these packs for so you can get a feel for what I’m working with.
![IMG_4785|375x500]Also: Now that I’m able to post links, here’s a link to my efoil build thread if anyone is interested.https://foil.zone/t/jsonnetts-latest-east-coast-build/6741/20
That’s a big banana.
I tried searching everywhere but to no avail…
Are there any CHARGE only smart BMS’s with BT that can handle up to 18S?
I know the LLT Smart BMS has BT and 18S but it has a very large physical footprint. Would like something that just does voltage readout really
There’s a cheat to do it, get a 18s bypass BMS from Daly or something then wire a 12s smart BMS from LTT in parallel for the first 12 cells
I have an ANT smart BMS with bluetooth and an optional display, but it’s not charge only, and is quite large. I think they’re available from 12 to 24s.
Doesn’t really matter too much for my application though (ebike).
But that would only mean you get a BT readout of the 12 cells connected to the LLT.
I want to run the BMS with Davega. I think the only option out there for 18S is the LLT atm?
Yeah you’d only get a readout for that section, but if 12 of 18 groups are perfect you should be okay
Although I’m not sure if they will have issue if they balance at the same time, you’d want to disable balance on the LTT so it’s read only
Or have 2 10s BMSs and double up the middle
At that point I’d just get one of the big ones.
