Emily VelascoStep one of rebuilding the e-bike my co-worker gave me is grafting a different battery management board onto the battery pack.
I still need to figure out how to wire up the charger plug. They used an XLR connector with four pins, and the charger doesn't turn the power on until it senses something (maybe a temperature sensor?)
Edit: i just needed to check the back of the charger for the pinout
A lot of fiddling later and i have the charging port connected and everything stuffed back in the original case.
It's Friday night hacker meetup and i am working on reviving the e-bike with the parts i ordered from AliExpress
It's gonna work!
That took hours longer than it should have because of dumb and fiddly little problems, but it's a working e-bike now. I just took it out and got it to to 24mph. That's faster than i like!
Things left to do: tidy up the wiring, figure out how to mount the pedal assist sensor, attach the headlight, give it a less boring paint job
fredy cosmoline 
@MLE_online you should coat it in bed liner, i hear that bed liner is a really good coating for bike frames
@fredy it is, actually, but only for those with the magic touch
@MLE_online that's true, it can sense if you are pure of heart
@fredy my heart is very pure. i wonder if i know anyone who has a heart of evil who's ever tried it
@MLE_online surely you'd never associate with such a sinner
@fredy Like the Christ, i seek out sinners and spend time with them. Only through their love for me will they be saved.