I’ve got a balance lead extension for a 6s pack where 1 wire is red and the other 6 is black. I’ve removed from the JST connector to run the wires through a small hole and it’s going to be frustrating to trace each cable back but then I thought, does it actually matter? It’s just 6 cells as long as the 7th red lead is correct does it matter the order for the others?
It’s just for balance charging and a voltage reader.
Thanks
It matters.
The charger needs to measure voltages across each cell so it knows what’s out of balance. Have had charger make magic smoke with a balance cable that was wonky.
Not hard to check. Use multimeter on each pin to make sure they are in the correct order, before you plug it in to the charger.
This is why I fuckin hate jst’s. They’re convenient only in theory.
In practice, 100% of the time the connector requires a bigger hole than the wires would, which leaves you with the options of “bigger hole, figure out how to seal it” or “redo the connector every fucking time you need to swap something involving it” and I hate both those options.
Do bullet connectors that small even exist? If so we could just chop em, add bullets, and easily reattach the connector inside the enclosure wall. That’d be dope. /Endrant
Buy these. 6 pin version.
NZ$ 4.75 7％ Off | 2pin/3pin 18AWG 4pin 20 AWG 5/6pin 22AWG 8pin Black Color Male and Female waterproof Connector For LED strip Applicable 0.75mm sq
Epoxy to the enclosure and crimp inside to jst to plug into esc. Cut off external jst from motor sensor wires and solder splice wires onto the external plug.
Those look great but here’s the thing: i hate soldering. I know that doesn’t mesh with my current lifestyle choices but it’s still true. I hate it so much. The smaller the thing, the more I hate soldering it.
If I was going that route, however, I’m usually running low enough specs that I could go 9 pin higo connector and skip the second hole for phases. Higo’s are “do the hard thing once and never do it again,” which fits my kinda lazy, and so I constantly contemplate switching all my shit over to them.
Fuck just done something stupid. Start removing the balance plugs before disconnecting from the battery and shorted it. It sparked, yanked the plug out, but the balance plug from the battery is toast. Battery hasn’t reacted but I am nowhere skilled enough to fix up balance plug connected to a battery.
So what now? Do I need to discharge and dispose? Can I discharge without the balance lead?
Just trying to not cause a fire now 
SOS!
Or can I just cut each wire individually and insulate with tape for now?
Again, I’m kinda stupid and not to be trusted, but I did similar with the actual battery leads after I sliced through both of em in one go on accident and took a nice relaxing spark shower. I used shrink wrap, not tape, to isolate. But the battery still worked just fine when I put a new xt90 on a couple weeks later.
Disclaimer: I have no idea how anything works and I am incredibly stupid.
If it’s just that end it just need to have a new crimp put on and slotted into new jst? Maybe? Have done that before. Don’t worry. Are you in CHCH, Matt?
Nah, Auckland. I’m thinking I will cut the ones that smoked/melted the connector individually and insulate them and then see if I can find somewhere locally that will crimp them for me.
Ok. I’m CHCH so can’t help sorry. But I bought a good crimper (Engineer pa09) and crimps and jsts from Amazon and AliExpress for like $50
It’s not that hard. Fiddly, and in nz you’ll need to wait ages for shipping but definitely possible.
Can’t speak for the upside down, but over here a crimp tool costs about as much as a crimp job.
There are also pre-crimped connectors available, I don’t have a link.
@rosco I love how we all low key favor the newbs that are local so we can have skate friends. That is all.
I’ve cut the two that looked shorted. One had no wire inside for about 2inches so I’m guessing it melted
I’d just leave them in the plug. Less risk.
What’s the other side look like? If you get a new plastic plug, You can probably carefully remove the wires one at a time (use needle) and put them into the new plug. Probably only need to fix that one wire.
Does the other end of the balance harness unplug from the battery (way safer if you can unplug the whole thing)
What’s the other end look like? Is it plugged into the battery (lipo?)
Can you simply unplug it?
Ok, again, not smart. But kinda clever. Sometimes. You’re probably gonna need a new connector. So get some. Take some pictures(you already did, but it’s good to go step by step for any future readers). Those will show the proper order of wires by color. One at a time, chop and isolate the wires. When new connectors arrive, you know what to do.
Nah, just peeled back the plastic wrap a little but they head in different directions so no plug to easily remove.
I think I’ve safely isolated any issues now and the battery itself looks safe to store.
Challenge now is to find somewhere local that will look at it or have a go myself at crimping the leads but feeling a little nervous about that.
If I test each balance lead with multimeter and voltage looks normal (it was around 3.8v per cell) is that a good indicator that all is well?
Good advice. Lucky I have two of exact same battery so have something to copy.
Bout 30 minutes ago I realized I can find out the proper order for the higo pins I need to replace on one side of my boosted motor thats fucked by stripping the other side, and restore my “tape everything on” method of test riding decks to full power. I have my moments.
I also have no clue how bms stuff works, so my advice might kill you. But cutting and isolating every wire one by one is usually the preferred method of safe teardown. If possible, do so with no power supply, but we humans are stupid as could be and therefore haven’t developed an off switch for battery packs.
