So I was thinking of getting a 36V 20Ah battery, controller is going to be separate (for my gravel bike project). There seems to be a baffling array of shapes and sizes, not all will fit 36V 20Ah. Is there an optimum case for a battery capacity.

 

Hailong Pro, Hailong Plus, Hailong G70, Hailong G56, Polly DP-4C, DP-5C, Hailong 2, XP01 etc

 

(I am buying a pre-built battery, just wondered if there was any advantages to it being in 1 casing or another)

I'm finding the battery switch more useful than I expected and they don't all have one. Bladed discharge connectors seem more reliable than round pins and similarly XLR charge sockets rather than barrel sockets, those are my must-haves. The drawings don't show how much space is needed to lift the battery forward and/or up to disengage it so ask on here if in doubt, and there are cases that detach sideways. People debate how strong the tabs are but I don't think that's an issue.

Just g3t one of the common ones so that replacement is easier in the future.