Battery packs, bms, amps beginner reading


Newly Enlightened
May 6, 2020
Hello, I'm new to this and wanting to make some 18650 battery packs for MTB night lights. Can anyone point me towards helpful reading to learn about discharge rate, how to choose bms board and things to look out for? Thanks.

A quick one also, does anyone know what this is, and if I build a replacement battery pack if I'll need one - it's on a 2s3p pack for a Magicshine MJ-880 MTB light -


Am I right in thinking that with cells hard connected in parallel they cannot be balanced charged, they are effectively one cell? So basically a bms will just be detecting that the cells as a whole aren't overcharged or over drained?

If I'm asking in the wrong place please give me some pointers as to where to look.

Thank you!