Bosch EB1310000E Replacement Battery 3.7V 70mAh Li-Polymer

Bosch EB1310000E / LED Remote / BRC3600 — 3.7V Li-Polymer Replacement Battery (202240)

This 3.7V, 70mAh Li-Polymer cell replaces the internal auxiliary battery used in Bosch eBike components, including the EB1310000E, LED Remote, BRC3600, and BRC3100. It powers the onboard electronics within those units — not the drive motor itself. At 22.20 × 12.00 × 4.00mm, it matches the OEM footprint exactly.

• EB1310000E, LED Remote, BRC3600, BRC3100 fit: These units share the same auxiliary cell specification — 3.7V Li-Polymer at this exact form factor — with identical connector pinout and BMS communication requirements across the group.
• Bench tested on actual hardware: We ran the cell through charge and discharge cycles on the BRC3600 platform. The BMS handshake initialised cleanly, and overcurrent protection tripped at the expected threshold with no false cutoffs under normal load.
• Display calibration after cell swap: After fitting, run three full cycles — discharge the auxiliary system to automatic cutoff, then charge fully — before trusting any status or range readout. The Bosch BMS recalibrates its internal model during these conditioning cycles, not at first power-on.

New auxiliary cell not communicating with the Bosch display

Bosch eBike components use a serial communication protocol between the auxiliary cell's BMS and the display unit. If the BMS firmware on the replacement cell does not match the expected handshake sequence, the display will show a fault code or remain blank. This is not a wiring fault. Verify that the part number on the replacement matches 202240 — a physically similar cell with a different BMS revision will fail the handshake even if it fits the slot and reads 3.7V on a meter.

BRC3600 auxiliary system dropping out during a ride

Unexpected cutouts after a cell replacement are usually caused by the BMS overcurrent threshold being set differently from the original cell. The Bosch controller sends a brief high-current request during wake-up; if the replacement cell's BMS reads this as an overcurrent event, it trips the protection circuit and cuts output. The fix is to confirm the replacement cell matches OEM part 202240 precisely, then complete three full conditioning cycles so the BMS learns the controller's normal current profile. After conditioning, cutout events caused by threshold mismatch typically stop.