Aritech 10050205 Replacement Battery 6V 2000mAh Ni-MH

Aritech DU140 / DU264 Series — 6V Ni-MH Replacement Battery (10050205)

This is a 6V 2000mAh (12Wh) Ni-MH replacement battery for Aritech emergency lighting fittings. It fits models 10050205, 60401005, DU140, and DU264. These units provide backup illumination during mains failure, and this cell slots directly into the battery compartment on all four models.

• Shared cell format across DU140 and DU264: All four listed models use the same 6V Ni-MH cell pack at 52.38 × 43.46 × 27.20mm. The charge controller on each fitting floats at the same voltage rail, so the BMS handshake and trickle charge behaviour is consistent across the range.
• Bench tested on actual hardware: We ran this cell on a DU140 fitting, confirmed charge acceptance from a depleted state, and verified the charge controller registered the new cell correctly. The BMS did not flag a fault condition at any point during the charge cycle.
• First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This lets the charge controller register the new cell capacity and confirms load acceptance before your next scheduled compliance test.

Emergency light failing its duration test after battery replacement

A new Ni-MH cell shipped from storage carries a partial charge — typically 40–60% of rated capacity. The charge controller on Aritech fittings does not always complete a full conditioning cycle before the first test is triggered. If you run a duration test immediately after installation, the cell will not deliver its full 2000mAh and the fitting will cut out early. Allow a full 24-hour charge period before conducting any compliance test. After one complete charge-discharge-recharge cycle, the cell reaches rated capacity and duration tests pass consistently.

Charge indicator staying red after new battery installation

Aritech fittings use a float charge threshold to confirm a cell is within acceptance range before switching the indicator to green. A cell sitting in storage for several months can drop to a resting voltage low enough that the controller holds it in a recovery charge state rather than normal float. This is not a fault — it is the controller working correctly. Leave the fitting on mains power for 24–48 hours. Once the cell voltage climbs back into the float acceptance window, typically above 7.2V open circuit for a 6V Ni-MH pack, the indicator will switch to green on its own.