Derby Cycle / Kalkhoff / BMZ Impulse

The batteries are 36V, 10s5p layout, 11 to 17 Ah capacity. They go under the names Kalkhoff, BMZ, or Derby Cycle. It does communication with the bicycle, but not with the charger. However, it can be discharged without special equipment, simply by connecting to + and -.

The main weakness of this battery is that water gets in and collects at the bottom end, rusting the cell group B1.

Wires on the BMS:

The BMS can be unplugged, no drama. On the right end, the two extremes are B- and B+, the middle are the discharge connectors.

BMS testing can be done /w the tester board!

Chargers

They come with 3A chargers originally, with XLR-4 connectors.

Pinout on original charger

1 - red

2 - yellow-green 

3 - blue

4 - NC

Pinout on the battery

1 - white

2 - NC

3 - black

4 - red

White is high when charging. 

To make a charger:

• Positive to 1 and 4
• Negative to 3

BMS tester board

It gets HOT when using it!!