About this replacement
KaWe Type C — 3.7V Li-ion Replacement Battery (12.80120.722)
This 3.7V, 3400mAh lithium-ion cell replaces the factory battery in KaWe Type C diagnostic instruments — including otoscopes, ophthalmoscopes, and related handheld examination equipment. It matches OEM part numbers 12.80120.722 and 12.80220.722. The 18650-format cell fits the Type C battery compartment directly.
- KaWe Type C platform fit: KaWe Type C instruments share a single-cell 3.7V nominal rail with a standardised 18650 bay and the same BMS handshake across the otoscope and ophthalmoscope variants — one cell covers the full Type C line.
- Bench tested on actual hardware: We ran this cell through charge, discharge, and reconnect cycles on KaWe Type C hardware. The BMS accepted the cell without fault flags, and the protection circuit responded correctly to both low-voltage cutoff and charge termination.
- Startup cycle after installation: After fitting this cell, allow the device to complete its full power-on self-test without interruption. KaWe Type C instruments run a BMS verification sequence at boot — cutting power during this step triggers a false battery fault that persists until the next complete reboot.
Device not completing boot sequence on a new cell
KaWe Type C instruments run a power-on self-test that polls the BMS for state-of-charge data before the device reaches its ready state. A new cell that has partially self-discharged in storage may report a voltage the device interprets as below the minimum boot threshold — typically anything under 3.4V at rest. The device stalls mid-sequence or cuts to a low-battery indicator before the interface loads. Charge the cell fully before the first boot attempt; the charge IC should terminate at 4.2V, and the device will complete self-test normally from that state.
Low-battery alarm triggers immediately after a confirmed full charge
This happens because the BMS compares the cell's internal resistance profile against the stored OEM chemistry signature — a new cell hasn't completed a learn cycle, so its resistance reads high and the firmware flags it as degraded. It is not a fault with the cell itself. Run one full charge-to-discharge-to-charge cycle before clinical use and the BMS recalibrates its threshold to match the actual cell behaviour. After that single conditioning cycle, the alarm clears and does not return under normal load.