how do i connect balance wires in parallel and series?

Hi everyone,

Few questions. So I have this idea where i have an 15s14p battery separated into 3, two 5s7p in parallel and one 10s14p in series. Im having trouble finding a 5s bms otherwise I’d put a bms on each pack. I have two 5s7p so i have the option to make the entire pack into a 10s by making series with the 5s7p’s together then parallel with the 10s14p. If anything were to happen to my HV vesc, i can just use a backup vesc onto 10s. I want to use one 15s bms in its 15s config and one or two 10s bms in 10s config, so my question is how can i parallel/series (not at the same time of course) the balance leads on the two 5s7p packs, then series/parallel that into my 10s14p pack, Id be willing to make adaptors for balance wires so it can work in both 15s and 10s configs. Worst case ill just make it one big pack or use a different voltage with easy to find bms.


The two 5s packs need to have the leads connected in parallel first, their combined balance lead can then be used in series with the 10s pack as usual.

do you have a diagram? i dont have a very good idea how to wire balance leads in parallel and series.

All In One Schematic / Diagrams

Respectfully, I don’t think you should be attempting this if you don’t know how to do this pretty basic setup.

But you’re going to anyway…:slightly_smiling_face:…so I’d like to task you with sitting down for a few minutes and drawing out the diagram of how you think it would be done. Post it here and then we can all discuss it.

This provides a much more effective learning opportunity for you, without asking someone else to do the diagram, and helps anyone else following this thread at a later date.


Precisely what I was gonna say before I just linked to the answer.

Usually I’ll send the answer and ask them to show they understand it.

Reverse ends up coming off as talking down which without your status seems cheeky

Last note is you change the word battery/cell to explosive you get an idea of what it sounds like when beginners ask for 101 advice.

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Nah, it’s cheeky no matter who asks. :joy:
But I strongly feel that if someone isn’t willing to chip in and/or they have no idea what’s going on then they shouldn’t be working on tripling up battery packs.

A willingness to put in some effort makes a big difference in how much time I’m willing to spend with a person. But that’s just me.


Heres my take in parallel and series. A while back, I got a pack that consists of 4 lipo packs and the guy wired balance leads in parallel and series and for some reason one of the leads were cut, i went to check the connector and the bms and it was a 12 pin (including negative) for a 12s battery and i thought there should usually should be 1 more pin than the actual S count for negative. I assumed it was not being used and got me really confused cuz it looked like it was a 11s wired for 12s battery.

Edit: i didnt ask the guy cuz i dont think he woulda remembered, he said he hasnt used it in a while. When i was picking it up from him he said it was 30q’s…so yeah. He was offering it for free so didnt mind.

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That’s a big short circuit. “P” on the bms is the main negative.

Shit you right, dunno why i thought main positive goes through bms.

Updated diagram:

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That looks better :+1:

Personally, i would give the 5s batteries their own little 6 pin balance leads and make a harness for the series connections for the 10s balance wiring.

Edit: @Regular_Michael made a great video on how to hook up 2 x 6s lipos to a 12s bms, same theory applies to 2x 5s for 10s. 12S BMS LiPo Hook Up - YouTube