mrbill
10 kW
Hi Folks:
I recently acquired two non-functioning e-bike batteries to see if I could revive them. After some testing and partial disassembly I discovered that the cells in both batteries were in good shape and all balanced, but the BMSs in both batteries were not working. Since these are "turn-key" e-bike batteries my first choice is to find a replacement BMS to pop in. Second choice is to use a 3rd party BMS if it fits within the original BMS's dimensions. Last choice is to use a 3rd party BMS that doesn't fit in the original case, and then discard the original case and make a "duct tape" battery.
Both of these BMSs have circuits for fuel gauges and multiple temperature sensors that are not necessary to duplicate should I need to substitute a 3rd party BMS.
The maximum continuous current on a replacement 3rd party BMS should be 25A or higher.
1) This BMS came out of a Varta battery. 10s LiPo. (dimensions: 4" x 3")
Two of the FETs have had their leads unsoldered. These FETs tested short when in-circuit, and I unsoldered their leads to confirm that.
2) This BMS came out of a BMZ battery. 10s LiPo. (dimensions: 4" x 1 15/16"). The part number at the lower right corner next to the B+ terminal on the BMZ BMS is "31020V2".
View attachment BB-20141010-0025.1.jpg
The three FETs on the upper right corner marked on the board with a black DOT tested bad.
The boards are square, even if they don't appear that way in the photos. I took the photos through a desk loupe.
Thanks for any help.
I recently acquired two non-functioning e-bike batteries to see if I could revive them. After some testing and partial disassembly I discovered that the cells in both batteries were in good shape and all balanced, but the BMSs in both batteries were not working. Since these are "turn-key" e-bike batteries my first choice is to find a replacement BMS to pop in. Second choice is to use a 3rd party BMS if it fits within the original BMS's dimensions. Last choice is to use a 3rd party BMS that doesn't fit in the original case, and then discard the original case and make a "duct tape" battery.
Both of these BMSs have circuits for fuel gauges and multiple temperature sensors that are not necessary to duplicate should I need to substitute a 3rd party BMS.
The maximum continuous current on a replacement 3rd party BMS should be 25A or higher.
1) This BMS came out of a Varta battery. 10s LiPo. (dimensions: 4" x 3")
Two of the FETs have had their leads unsoldered. These FETs tested short when in-circuit, and I unsoldered their leads to confirm that.
2) This BMS came out of a BMZ battery. 10s LiPo. (dimensions: 4" x 1 15/16"). The part number at the lower right corner next to the B+ terminal on the BMZ BMS is "31020V2".
View attachment BB-20141010-0025.1.jpg
The three FETs on the upper right corner marked on the board with a black DOT tested bad.
The boards are square, even if they don't appear that way in the photos. I took the photos through a desk loupe.
Thanks for any help.
