Ericsson 40070149 Flashlight Replacement Battery 6V 5000mAh

Ericsson SLX200 Flashlight — 6V 5000mAh Ni-MH Replacement Battery

This is a 6V 5000mAh Ni-MH battery pack for the Ericsson SLX200 flashlight. It fits units listed under model references 40070149 and 41B038AF00101. Capacity is sourced from the product specification — 5000mAh, 30Wh.

• SLX200 platform fit: Both 40070149 and 41B038AF00101 share the same cell count, pack voltage, and connector arrangement. The SLX200 driver circuit expects a 6V nominal input from this Ni-MH configuration — swapping with a different voltage pack will trigger protection cutoff or cause driver malfunction.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the SLX200 platform. The BMS accepted charge without error flagging, and output voltage held stable across draw levels typical of this flashlight's driver stages.
• Multi-cell replacement rule: The SLX200 pack contains multiple cells in series. Always replace the full pack as a unit — never attempt to re-cell with mixed old and new cells. Under high-current draw, a weaker cell will drain first, reverse-charge against the others, and permanently lose capacity within a few cycles.

SLX200 dimming before the battery indicator reads low

Ni-MH cells have a flat discharge curve that drops sharply near end of charge. The SLX200 driver detects voltage sag under load before the indicator circuit registers the drop at rest. When the pack voltage falls below the driver's brownout threshold — typically around 4.8–5.0V under draw — the driver steps output down to protect the LED. This is not a fault; it is the driver preventing damage from under-voltage. A fresh, fully charged pack resolves it immediately.

Pack not taking a full charge after extended storage

Ni-MH cells that have sat discharged for months can develop voltage depression — individual cells drop so low the charger's detection circuit reads the pack as already full or faulty. The fix is a controlled low-current conditioning charge, sometimes called a trickle or recovery charge, at around 0.1C — for this 5000mAh pack, that is approximately 500mA. Run one full conditioning cycle before returning the pack to normal duty. If the pack fails to recover to at least 5.5V rested after two conditioning cycles, the cells have sulfated beyond recovery and the pack needs replacement.