n00b BMS hookup question

Hi, sorry if this is an easy one but I did search quite a bit.

I'm building a 20S 12P pack for my Qulbix 76R. I took a break from Fall to now and everything I thought I knew (or bought) is now making me scratch my head. Cells are Samsung 25R, controller is an 18F Bluetooth from Powervelocity.com

I followed Quokkas excellent build and am to the point where I'm finishing spot welding the nickel sheets. The next step is to solder on the BMS leads. I bought a BMS from SuPower Battery, seems they were well regarded. I have the 20S 100A version.

First off is that the right A for my bike/pack? I couldn't find anything larger at the time but maybe I bought in haste.

The literature in the package has instructions for B- ( to battery -VE) which seems fairly obvious

Then it states that P- is -VE for both discharge and charging. All the other threads I have found have a C- wire, mine does not. Just B-, P- and 20 balance wires.

Any help on the this up for a noobie bike builder?

You can use the P- for charge and discharge...so P- wil be C-/P-
B- battery and the sense wires you can see easy on the literature.

can you see the awg wire size on the B- P-.....looks smal to me for a 100A bms?

Thanks Joachim, I was hoping it would be a simple answer.

Your suspicions were mine as well, I thought the wire sizes looked pretty small too. Which is why I was asking if this was an appropriate sized BMS. There are no marking on the wire at all but I measured with my calipers and got 0.100 which appears to make these all 10 AWG.

Just so I'm clear, I'll solder both B- leads to the negative nickel pad on my battery. The Yellow P- will go to the negative lead from my controller. Positive from my battery will go to red positive on my controller. That's it yes?

Interestingly I just brought over my controller so I could match up wires. The pos/neg wires on the controller are both smaller than the BMS system. I can't see actual wires but measuring over the sheath is 0.136", but maybe they are 10 AWG too.

Battery building is NOT an easy task especially cutting those sheets of nickel!

Nice pack :wink: