12S-3P Battery module

It’s been a while since I’ve made a post, so I’ll try to do my best :blush:.

This is a brief walkthrough on assembling the custom 12S-3P pack module, this system is use in parallel on a 9P or 12P configuration.

I’ve made this in order to save time wiring, low profile, proper separation of cells and a few more reasons…

Cell configuration
The cells are configure into 2 identical 6S-3P stacks as in this picture

The series connectors plates help with alignment and the balance tabs connect to the pcb, also the balance tabs are oriented to match the solder pads on the pcb.

Pack A, negative side.

Pack A, oposite side.

Pack B, positive side

Pack B opposite side.

Packs positioning side by side, Pack A in front.

Attaching packs to PCB
For this the balance tabs are aligned with the corresponding solder pad and spot welded into place.

Then a separator goes in between the packs with the help of 300LSE tape.

Next is pack B

The series connection from pack A to B is made by using a 3 layer nickel strip.

Now add isolators side pads

BMS 30A and balance connector.

Next shrink wrapping.

The individual enclosure for this packs are made from aluminum and powder coated with a notch for the discharge wires.

The trays can be aligned side by side.

I use fiberglass tape for rigidity and cover with flashing tape to seal it, this configuration provides the best flexibility and proper water resistance.

The packs fit tight into the tray and we use silicone to glue the packs to the tray.

Now you can assemble this into a 12S-12P, or 12S-9P.

Next is the parallel connection.
Since each pack can discharge up to 30A the total output will be from 90A to 120A, but in real world situation I’ve never pulled more than 60A from a battery pack.

This are the main discharge tabs.

A 12AWG wire is solder directly to the tabs and to the output and charge port.

For the 12P

For a 4x4 set up the discharge wire con be extended to both ends.

To seal all up a double layer of 300LSE tape and a plastic cover.

That is all for now :stuck_out_tongue_closed_eyes:


Phenomenal write up man. Well broken up with lots of photos. I appreciate you taking the time to do this.


@Kaly what kind of wire management god are you… this is so NEAT




This is great u have raised the bar for Esk8 battery’s.


Looking good man. So do you have these available as kits?


Looks great!

Where do the esc’s go for 12s12p?

What are you doing up so early/late posting a complete write up?

Why spot weld to the pcb? I thought it was better to solder.

I only spot two layers of nickel connected to a third on the battery. That counts as three then?


on top


Well yes I figured as much. But considering his builds, I haven’t seen any top mount esc enclosure.

I am wondering if he has something kaly special coming out for that.


There is a special enclosure but I cant find a pic for it easily



Thanks for sharing that. Impeccable work and nicely put together.


Thanks guys for the kind works :pray:

@ducktaperules will have it, by Late next week should have a few kits available.

@esk8manbabes was up early, so went for it.
Spot weld is way faster than soldering :grinning:.

@moon thanks for the pictures.


Whats the idea behind having solid nickel strip the first and last 3P group but inbetween of the pack the nickel is cut out to thinner connections?
I guess it’s meant to work like cell level fusing, but why than no cut out on the plus and minus terminal of the first and last p-group?

If it’s no secret, is that 0.15 or 0.2 nickel you use?

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Does anyone see any concern for lack of fish paper between P groups, the bottom of the pack and the aluminum enclosure, and some of the thin nickel?

This looks way better than anything I’ve made, so i’m just curious… and regardless this is all super sexy and super clean!


Plenty of Kapton and siliconed down, so won’t be rubbing up against anything.


if configure the way you suggest the main negative and positive will end up being side by side at the center and a potential soldering mistake will be BAD, better this way and assembly efficiency is increase.

Nickel 0.20

The fish paper is optional since there is a gap between the top of the cell positive contact and the negative body of the cell, by having proper alignment this is not a problem.


I think my English is not good enough to express what I mean :joy:

Basically why the nickel in red marked are solid and the blue marked nickel has special cut out?

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I don’t think it’s too thin. Don’t forget that’s only a 3p pack and that’s not going to be used as single 3p pack. If you run 3-4x of this packs parallel the current will also be shared between the packs.


that is to improve efficiency in the assembly process.

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