lululock OP t1_je1010x wrote on March 28, 2023 at 5:08 PM

Reply to comment by Spritzer2000 in Microsoft Surface Pro 4 battery pinout by lululock

You're right... I guess I'll salvage the BMS from another dead battery which hasn't expanded yet. I'll ask a few repair places around. Maybe they could even strip out a BMS for me.

But then comes the part where I'll solder new cells to it. Do you think it will get the extra capacity of 18650 cells ?

Spritzer2000 t1_je151mq wrote on March 28, 2023 at 5:39 PM

If it's done properly, I don't see why not. The only thing that might get in the way will be if there's an individual bms system in each cell that handshakes with the "central" system. I haven't actually cut into batteries in a while, generally only replace them

lululock OP t1_je163p2 wrote on March 28, 2023 at 5:46 PM

I've found a picture of a BMS someone took appart.

The left one is from a Chinese copy but the right one is the original LG one. Looks like both cells would connect to it. Comments say that the original BMS has a temperature sensor and charging control and that's why some Chinese copies won't get recognized by the Surface.

I think I'm getting somewhere with my idea.