Clarity C440 Cordless Phone Replacement Battery 3.6V 1200mAh

Clarity C440 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1200mAh Ni-MH replacement battery for the Clarity C440 cordless phone handset. It slots into the handset battery compartment and restores talk time and standby function when the original cells have degraded. Voltage and connector match the C440's charging circuit directly.

• C440 handset fit: The C440 runs a single 3.6V Ni-MH cell pack with a fixed connector and polarity. This replacement matches that configuration — same pin layout, same voltage rail, same physical footprint at 50.43 × 42.54 × 14.40mm.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Ni-MH compatible tester. The BMS held the cells within spec, and the pack accepted a trickle charge from the base station without triggering an error state.
• First charge on the C440 base: After installing, seat the handset in the base for a full 16-hour charge before use. Ni-MH packs ship in a partially discharged state — a slow first charge lets the cells reach rated capacity and sets the baseline for subsequent cycles.

Base station showing no charge light on a new Ni-MH pack

Ni-MH packs drop to low resting voltages during storage and shipping. Some cordless phone base stations — including Clarity models — check for a minimum voltage before initiating the charge cycle. If the pack is too far below threshold, the base sees it as absent or faulty and withholds the charge current. Placing the handset in the base for 30 minutes, removing it, then reseating it often prompts the base to retry. If the pack has rested below 3.0V, a compatible external Ni-MH charger can prime it back above the acceptance threshold before returning to the base.

Talk time shorter than expected after fitting a new pack

New Ni-MH cells don't deliver full rated capacity on the first cycle — this is normal chemistry, not a fault. The cells need three to five full charge-and-discharge cycles before they reach 1200mAh. Each cycle, the pack will hold slightly more charge than the last. Run the handset down to low battery warning, return it to the base for a full charge, and repeat — by cycle four or five, talk time should stabilise at rated capacity.