About this replacement
Ledlenser MH7 / MH8 — 3.7V Li-ion Replacement Battery (500987)
This 3.7V, 2000mAh Li-ion cell replaces the original battery in the Ledlenser MH7 and MH8 rechargeable headlamps. It slots into the same battery compartment and connects to the same charging circuit. Voltage and capacity match the OEM specification exactly.
- MH7 and MH8 compatibility: Both models use the same battery housing, connector orientation, and charging circuit. The BMS on each headlamp expects a single 3.7V Li-ion cell with the same protection thresholds — one battery fits both without any modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the MH7 platform. The BMS accepted the cell without error, hit the correct 4.2V charge termination, and the low-voltage cutoff triggered cleanly at 3.0V before the driver started stepping down output.
- Turbo mode draw on the MH7: Turbo mode pulls significantly higher current than standard modes. Keep the cell at a healthy state of charge before extended turbo use — a partially depleted cell hits brownout thresholds faster, causing the driver to step down output even when the indicator shows charge remaining.
MH7 dimming before the battery indicator reads low
The MH7 driver uses brownout protection that steps output down when cell voltage drops under load — not when the indicator triggers. A degraded or partially charged cell sags below the driver's threshold during high-current draw, so the light dims even though the indicator still shows green. This is not a fault — it is the driver protecting the cell from over-discharge. Switching to a mid-power mode restores full output because the current draw drops and cell voltage recovers above the threshold.
MH7 flickering between modes at the end of a charge cycle
When cell voltage drops close to the driver's minimum operating voltage, the MH7 can cycle between brightness levels rather than holding a steady output. The driver is repeatedly attempting full output, hitting the brownout threshold, stepping down, then recovering — a loop that looks like mode-switching. This happens more often with aged cells that show high internal resistance and sag quickly under load. Replacing the cell restores stable voltage above 3.3V under draw, and the cycling stops.