It’s not great because if one pack tries to drain a little faster the balance leads will carry a lot of that current difference
If you have different batteries the side that drains first will have less kick so the other one will drain to match and it will balance out but if you connect them with balance leads you will kill the pack (until you repair it which will suck because now you really need another BMS lol)
I’m almost convinced to build the two battery system… yeah I’ll need another 12s BMS (Hey @jack.luis I found a use for that spare BMS we were talking about… )
this would be super redundant and on direct-drives I could motivate myself home without drama if one whole drive system failed, and if this is not fun… I know where I could put a couple of 12s2p batteries…
I’m gunna think about it, and sketch up some wiring
tanks meng
Having long and narrow batteries would also be the same, just longer balance leads…I’d decide based on if you think you’ll have other uses for 450mm battery again
Did you glue 2 pics together? Lines don’t line up
so now you’re an art critic… yeah…
I didn’t want to drive to the shop to get my other ESCs
and the technical term is “stitch” or “'shop”
am I good to go now?
I “think” I’m going to Go for the big “C” 12s4p
looks easy-peasy except for the balance wiring… that will be a NIGHTMARE
EDIT:
nah… it’ll be fine just a bit unusual…
Every time I see one it really takes me back… so many mistakes ago
That whole paralleling packs through balance leads thing interests me.
Might try it on my kweld 3S packs
I didn’t wanna fix it yet cuz I’ll have to redo the shrink wrap and that’s a bitch to do with the size I got lmao.
Guys using lipos in other hobbies do this all the time. they charge up their packs all off one charger by plugging them all in parallel. They just have to be at the same voltage when you connect them.
like this:
You sir just made my day. I noticed 4x 6s 5ah LiPo charging off one charger is a pain in the ass. Gonna get me a parallel charging board. Now, if only I didn’t have to make xt60 to xt90 adaptors 
Sidenote: this info is pretty interesting
Sooo… I’m bored and got the itch to weld some cells. I’ve got this 10s2p laying around. Anyone got some ideas on what I could do with it ?
Emergency phone battery bank! Or maybe separate light battery source?
Liking this idea
Those parallel charge boards never gave me much confidence honestly.
Before I had a proper balance charger I charged 4x 6s packs in 12s2p combination, but just connected 2x6s lipos with balance wires. To the parallel pack I added some voltmeter like this
To monitor that no cells get over charged.
If you have proper lipos with similar IR they should top out pretty much at the same time.
If no I disconnect the packs and gave each 12s1p combo some individual minutes on the balance charger
How would I charge in 12s? Not use balance leads? I prefer staying on the safe side, I can’t be next to the batteries at all times, 3 kids to take care of 
Honestly it’s really convenient to have a 10s1p around loose for testing, it lets you power things up without having a massive battery you tore from a working board. I am going to be keeping a 10s1p 30Q for motor testing and what not, like a mini power supply
Then also do not use parallel balance boards.
Especially with older lipos shit can happen. If one cell is fucked there is a risk of overcharge one cell.
In general i wouldn’t recommend to let lipos charge while being somewhere else in the house.
Get yourself a JB balance board, it’s got all sorts of good protection features you probably could use.
