About this replacement
Biocam Dermogenius Basic — 4.8V Ni-MH Replacement Battery (120284)
This is a 4.8V, 800mAh Ni-MH replacement battery for the Biocam Dermogenius Basic portable dermatological device. It fits both the standard Dermogenius Basic and the hand magnifier Dermogenius Basic variants. OEM part numbers 120284 and BATT/110248 both cross-reference to this cell pack.
- Dermogenius Basic platform fit: Both Dermogenius Basic variants share the same 4.8V battery bay, connector pinout, and BMS handshake. The cell pack dimensions — 49.50 x 23.50 x 19.50mm — match the original housing without modification.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on the Dermogenius platform. The BMS accepted the cell on first insertion and passed the power-on self-test without triggering a fault code. Charge termination occurred cleanly at full capacity.
- Post-installation self-test protocol: After fitting this battery, allow the device to complete its full power-on self-test without interruption. The Dermogenius runs a BMS verification sequence at startup — cutting power mid-cycle stores a false battery fault that persists until the next clean reboot.
Device not completing boot sequence on a new Dermogenius battery
The Dermogenius Basic runs a BMS learn cycle during its first few charge-discharge passes. A new Ni-MH cell starts with an uncharacterised internal resistance profile, which the device's charge IC reads conservatively. If the boot sequence halts or loops, the BMS has not yet accepted the new cell's baseline. Run one full charge to termination, then a full discharge under normal use, before treating the battery as clinically ready. After that first cycle, boot behaviour normalises.
Low battery alarm triggers immediately after a confirmed full charge
This happens when the device's BMS compares resting cell voltage against a threshold calibrated to a worn OEM cell. A fresh Ni-MH pack at 4.8V can show a slightly different voltage curve than the degraded cell it replaced, causing the alarm logic to misread state-of-charge. The fix is one complete charge-discharge cycle — after that, the BMS recalibrates its threshold to the new cell's actual curve. Confirm resting voltage sits above 4.5V before starting the cycle.