DIY backfire battery replacement

Hey guys and girls. First post woo!

Ok so my brand new but old model backfire battery has dropped 2 cells and backfire will not help at all so I need a DIY battery fix. Atm it has 6 flat packs, so do I need to recreate 6 packs? I could fit 7s6p with samsung 30q which is not going to be high speed at 25.2v but I’m not trying to ride fast, I’m training for snowboarding so its all about body movements. Slow is ok. Range is paramount.

So should I 7s6p or 8s5p or 10s4p this thing back to life?

Thank you for taking the time to ease my spinning mind.

Hi, I used to ride a backfire g2 the esc is designed for 10s so best to stay with that. I also have a verreal v1 that i modified to 10s4p instaed of 10s2p and it made a huge difference for performance. You might be able to bring the old pack back by measuring the voltage in each p-group with a multimeter and slowly charge each individual p-group back to balance so the bms will charge them. One or two p-groups could have gone below the max discharge threshold (2.5v-2.7v ) of the bms.

Thanks Ando. 2 of the packs have continuity across the terminals and 4 don’t so I assume they are toasted?

I’m not really sure what dropped 2 cells means, but have you cut the plastic off the packs and found something damaged inside? There can be any number of problems that could have occurred. Have you checked the voltage of the pack?

Backfire uses plastic cell spacers so you have a little extra room in the enclosure, you want to keep with the 10S2P config for sure but pick a higher capacity cell like the sanyo 20700b’s which are similar to the 30q’s but have an extra 1000mAh per cell and may fit. You can buy one from Meepo or have someone on the forum build one for you (in your continent/country international shipping of batteries is a serious pain).

In fact it does fit, see the size comp,

It has 6 flat cells and 2 are not working, I’m no electrical expert, but I get by. There is no 10s2p going on here. There are 6 wires coming from 6 flat packs going into the bms. I would call it a ?s6p. They look like laptop batteries