Tele-Phone TEL5000 Replacement Battery 3.6V 600mAh

Tele-Phone TEL5000 / TEL6000 Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 600mAh Ni-MH rechargeable battery for the Tele-Phone TEL5000, TEL5050, TEL6000, and TEL6050 cordless handsets. It slots into the handset battery compartment and restores cordless operation when the original cell no longer holds a charge. Voltage, capacity, and physical dimensions match the factory specification.

• TEL5000 / TEL6000 series compatibility: These four handset models share the same 3.6V cell format, connector orientation, and compartment footprint — 42.64 × 30.00 × 14.45mm. One battery fits across the range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Ni-MH test rig. The BMS accepted charge from the base station cradle without triggering an error condition, and terminal voltage held stable across the full discharge curve.
• First-charge protocol for Ni-MH handsets: After fitting the battery, seat the handset in the base station and leave it for a full 16 hours before using it. Ni-MH cells ship partially discharged — the slow first charge lets the cell reach rated capacity and sets the baseline the base station uses to detect a full charge.

Talk time shorter than the original battery after replacement

Ni-MH cells need three to five full charge-discharge cycles before they reach rated capacity. A new cell pulled straight from packaging will underperform for the first few uses — this is normal chemistry, not a fault. Each cycle conditions the cell and gradually increases the usable capacity. By cycle four or five, talk time should match or approach the 600mAh rated figure.

Base station shows no charge or error light after fitting new battery

Ni-MH cells lose charge during storage and can arrive at a voltage below the threshold the base station uses to detect a connected battery. When the resting voltage is too low, the base may display an error light or simply not begin charging. Remove the handset, wait 30 seconds, then reseat it firmly — the base retries detection on reconnect. If the error persists, check that the handset contacts and cradle pins are clean and making full contact before assuming a fault.