TCM 68143 Cordless Phone Compatible Battery 3.6V 700mAh

TCM 68143 / CP731 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH replacement battery for TCM cordless phone models 68143 and CP731. It fits the handset directly, restoring power to the unit when the original cell no longer holds charge. Voltage and capacity match the original specification exactly.

• 68143 and CP731 compatibility: Both handsets run the same 3.6V single-cell NiMH pack with an identical footprint — 44.74 × 20.77 × 10.50mm. The connector orientation and BMS handshake requirements are the same across both models, so one cell covers the pair.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a NiMH-compatible test rig. The BMS accepted charge current without trip events, and cell voltage held stable across the full discharge curve down to the 1.0V per-cell cutoff.
• First-charge protocol for NiMH handsets: After installing the new battery, seat the handset in the base station and leave it for a full 16 hours before first use. NiMH cells ship in a partially discharged state — a slow initial charge is required to bring all cells to rated capacity and establish consistent cycles going forward.

Talk time shorter than original battery after replacement

New NiMH cells do not deliver full rated capacity on the first cycle — this is normal chemistry behaviour, not a fault. The cell needs three to five full charge-and-use cycles before the electrolyte fully activates and capacity reaches 700mAh. Each cycle, talk time will increase noticeably. Run the handset until it prompts a low-battery warning, return it to the base for a full charge, and repeat. By cycle five, capacity should be at or near the rated figure.

Base station not charging after inserting a new NiMH pack

TCM base stations check incoming cell voltage before enabling the charge circuit. A NiMH pack that has sat in storage can drop low enough that the base reads it as a fault condition rather than a dischargeable cell. If the charge indicator stays off or shows an error, remove the handset, wait 10 seconds, and re-seat it firmly — this resets the detection cycle. If the base still does not respond, check that the cell voltage is above 3.0V with a multimeter before concluding the base or battery has a fault.