EM3ev has replacement controllers BBS01 36v 18a, 24v 15a, and 20a. $80
This a replacement controller intended for the 36V Bafang BBS01, it can be used with either the 250W or 350W version BBS01, but is not suitable for the 36V 500W. As can be seen in the images, the controller includes a section of the motor housing and all connnections. It may be necessary to change the battery supply connections, it does not come with the molded waterproof supply connection. The connections, housing etc do add quite a bit of cost, so it is relatively expensive.The sealed PCB makes them rather difficult to do a DIY repair, so it is much more practicle to simply swap the controller section.
The standard settings are as follows:
LVC (low voltage cut) 30V, suitable for 36V battery. Not suitable for 48V.
Will be configured so the throttle gives 100% assist no matter which assist level is selected.
Number of assist levels are adjustable by the display.
Wheel size can be adjusted from the display.
Speed limit can be set via the display.
Bafang BBS01/02 Mid Drive Kit Manual: http://1drv.ms/1fdhZM2
Bafang C961 Display (for BBS02 Kit), which includes how to get into the settings and advanced settings menus to change various parameters:http://1drv.ms/1gSHNz5