Custom battery pack

im building my second electric longboard and am looking to use 18650 batteries this time around. I already ordered some LG batteries 20 of them which I will be using as 2 10s parallel packs. Which BMS do I need and how do I get it all set up to where I just need to plug one wire into the board and wait till its done charging? Thanks!

Multiple threads on this basically u need a bms and a charger that works at that voltage until you figure that out there isn’t much I can say except read a bit more

Tons and tons of threads on this. Search for custom 18650 battery, BMS - those will be the big ones to learn how-to.

Couple suggestions though - a 2p battery is going to be a bit anemic. OK on the flats, but not much amp capacity/delivery so you will have BIG voltage sag under heavy load, and reduced pack life. I would suggest at least 3 or 4p depending on the specific cells you chose. LG is too generic - they have 2A cells and 20A cells… and everything in-between…

Any lipo BMS will work - you want a 42v BMS for 10s. Or skip the BMS and balance charge w/ regular hobby lipo charger (likely two 5s packs for less expensive charger).


could you explain why the 2p wouldnt be enough and how doing 3p or 4p would be better? thanks

Amp delivery…more amps = less sag. Typically a 10s2p gives 30 amps, a 10s4p gives 60 amps. Although I have multiple 10s3p packs, made with Samsung 30Q cells, that deliver amps for days…more than I can use.

Hey man - this is exactly what i’m talking about - you need to do more research before you buy cells and build your own.

I answered your question in my initial post:

Amp delivery and sag. If you don’t understand how the specific cells affect performance (how many amps can they supply, and how increased #'s in parallel help) - you really should read more and get your knowledge to an acceptable level before throwing money at something that might work poorly if at all.

If you have a plan - specific cells and layout - i’d suggest posting it up for folks to comment and help. Not trying to be a jerk about it, and everyone has to start somewhere… but also trying to help you avoid buying components that will not work at all, or will work really really poorly. Could be a complete waste of money if you aren’t careful.

Let us know the specific cells you want to use. I’d still suggest at least a 3p. This also depends on the area you ride (Flat vs Hills), single/dual setup, and your weight (how big of a draw on amps to move you)?

HTH and GL!

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