12s4p 25R Pack for Sale

Hey there! :alien:

I recently built a 12s4p pack, charged it once, used 2ah, and blew my vesc. :sweat_smile: The pack is made of 48 Samsung 25R cells(444wh,<80amps max), 10mmx.15mm pure nickel strips, and 10 awg wire.

The BMS somehow stopped working with it, so I am selling the raw pack with balance cables and full insulation Here is what it looks like:

This is the orginal BMS that I was planning to use.

I sandwiched the balance leads between kapton tape on top of the batteries. And used 10awg segments to connect the sides so the pack could be slightly bended. 180mm heatshrink avaliable for free. :fire:

US only from Belmont, CA

Price: 280$ shipped. (paypal goods & service) Includes the 12s4p 25R pack seen (NO BMS)


regardless of the fact that it probably wasn’t the battery’s fault, I still don’t think that’s the best thing to say when selling a battery pack


I think I know why your bms won’t work with it…

correct me if I’m wrong but those look like open solder joints

I insolated them with Kapton tape. You can see that they those segments are deeper in color. I also ran it for 7 miles and they worked fine. Shouldn’t they catch on fire otherwise?

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Catching fire totally depends… I didn’t realize that they were each insulated separately, so that wouldn’t be the problem then. Either way if you’re selling a battery, I believe each and every solder joint should be properly shrink-wrapped


exactly what i wanted to say, i would never every use kapton to seal solder joints. they can get loose so easily.

Man… such a good deal. Shipping to Australia? Nah import make it way too expensive. Good deal for someone.

Out of sheer curiosity, where did you get that BMS and what are the specifications of it?

i am also interested in that BMS. Just looking at the number of fets onit… what is that, 30 amps maybe?

No? As a noob tell me why not? Would you have preferred to use heatshrink or electrical tape?

kapton or technically spoken, polyimide is an insulator and heat exchanger. kaptop is a very thin tape, shrink tubes are tubes with a lot more thickness.

kapton is not good for mechanical exposure, which a battery pack could be in the enclosing.

think of driving over cobblestone, the wires will start shaking, maybe you got one little braid of the cable not tinned or soldered right, it will poke through the kapton easily.

always use shrink tube!


“Kapton insulation ages poorly: an FAA study shows degradation in under 100 hours in a hot, humid environment, or in the presence of seawater. It was found to have very poor resistance to mechanical wear, mainly abrasion within cable harnesses due to aircraft movement. Many aircraft models have had to undergo extensive rewiring modifications—sometimes completely replacing all the Kapton-insulated wiring—because of short circuits caused by the faulty insulation. Kapton-wire degradation and chafing due to vibration and heat has been implicated in multiple crashes of both fixed wing and rotary wing aircraft, with loss of life.”