I ordered this cheap BMS from ebay. It uses a the same balance connector as my battery pack, but the location of B- on the battery's connector and on the BMS's connector extension are opposite! The connector extension has one black lead (this extension shipped with the BMS) which I assume is B-.
Since the BMS board is unlabeled, I'm not sure if the lead extension is just wrong, or if the board actually has its B- wire opposite of my pack.
=/ What can I do?