this is what i use for all my ev's now. it is 48v 20ah charge. it has worked very well and has held up being balled up in the cargo box and along for most rides. it has a built in fan that makes some noise but if i wanted i could sit next to it and read a book. the ports i put on my bikes come out of a old desktop computer or out of a guitar amp. both use the same plug.
speed has never killed anyone, suddenly becoming stationary...that's what gets you.