Uniross CP76 Cordless Phone Replacement Battery 3.7V 600mAh

Uniross CP76 — 3.7V Li-ion Replacement Battery

This is a 3.7V 600mAh Li-ion replacement battery for Uniross cordless DECT phones using the CP76 cell. It replaces an original battery that no longer holds a charge and restores normal handset operation. Fit compatibility is based on the CP76 part number — confirm this matches your handset's existing battery label before ordering.

• CP76 form factor: DECT handsets using this cell share a common 3.7V single-cell Li-ion rail with a fixed connector pinout. The BMS in these handsets communicates charge state directly through that connector, so the replacement cell must match voltage exactly — a mismatch trips the charge controller.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a cordless phone platform. The BMS accepted charge from the base station without fault, and the protection circuit responded correctly to low-voltage cutoff at the expected threshold.
• First charge after installation: Place the handset in its base immediately after fitting this battery and leave it for a full charge cycle before using the handset. Li-ion cells shipped in storage state need one complete charge before the fuel gauge in the handset reads capacity accurately.

Talk time shorter than original battery after replacement

A new Li-ion cell arrives partially discharged from storage — typically at 30–50% state of charge. The handset's fuel gauge calibrates against that starting point, so it underestimates remaining capacity until a full charge-discharge cycle resets the reference. This is not a fault with the cell. Run two or three full cycles — charge to 100%, use until the handset signals low battery — and the gauge will stabilise against the actual 600mAh capacity.

Base station not charging after battery swap

Some DECT base stations use a voltage threshold check at the start of a charge cycle — if the incoming cell is below roughly 2.5V from deep storage, the base interprets it as a fault and refuses to begin charging. Remove the handset, hold the battery in a warm room for ten minutes, then reseat it in the base. If the base still shows no charge activity, use a standalone Li-ion charger set to 3.7V to bring the cell above 3.0V first, then return it to the base.