I got this 2019 Rad Rover with 1100 miles on it a few days ago and so far I put 60 or so miles on it.  Everything was working well but when it got to two bars left it died very quickly thereafter, totally shutting down so I thought something was up with the battery.

Charged it up fully for 12 hours to try to let it balance and after 23 mile ride, all cell groups were at 3.58 and this cell group was at 3.44

So I attached my alligator clips to the two cell group tabs to charge at 4.2v and somehow I must have touched them to the circuit board in the exact wrong spot and whooof a big spark and lots of smoke. I am left with a tab that has melted itself off the circuit board.  So yeah I totally screwed myself trying to "fix" something.  There's nothing left on that circuit board to resolder the tab back to..all the metal is gone.

So I did a search and found user dickb has created a very detailed and extremely helpful guide to replace the BMS with an aftermarket bms on this exact battery (rad 48v 14ah)

I've already ordered the same BMS he used from greenbikekit.com

Here is a link https://ibb.co/XyBhcnp  to the image of the damage and a link to user DickB's wonderful guide https://www.radowners.com/index.php?topic=1647.0