AT&T Lucent TL1000 Cordless Phone Compatible Battery 3.6V 700mAh

AT&T Lucent TL1000 / TL1200A Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH battery for the AT&T Lucent TL1000, TL1100, TL1102, and TL1200A cordless phone handsets. It slots directly into the handset battery compartment and restores full wireless operation. Capacity is 2.52Wh — matched to the original spec.

• TL1000 / TL1100 / TL1102 / TL1200A shared platform: These four models run the same 3.6V single-cell Ni-MH pack with an identical connector and footprint — 45.60 × 31.30 × 10.60mm. The base station charges all four handsets at the same trickle rate, so one battery spec covers the whole line.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Ni-MH-compatible tester. The cell accepted a full charge without thermal runaway, and the terminal voltage held above 3.4V through the discharge curve — consistent with rated capacity.
• First-charge protocol for Ni-MH handsets: After installing, seat the handset in the base and leave it for a full 16 hours before first use. Ni-MH cells shipped in a partial state of charge need that slow initial cycle to reach rated capacity — cutting it short will leave you with noticeably shorter talk time from day one.

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

AT&T Lucent base stations use a delta-V detection circuit to confirm charging. A new Ni-MH battery arriving from storage at a very low resting voltage — sometimes below 3.0V — can fall outside the window the base expects to see. The charger interprets this as a fault rather than a flat cell and stops the charge cycle early. Placing the handset in the base for at least 30 minutes, removing it, then reseating it usually allows the circuit to re-enter the charge phase once the cell voltage climbs slightly.

Range drops noticeably mid-call after a battery swap

DECT handsets pull a short burst of RF transmit power during each voice packet — this creates a momentary current spike the battery must absorb without voltage sagging. If a Ni-MH cell hasn't been through at least three full charge-discharge cycles, its internal resistance is still elevated and the voltage dips under that RF load. The handset interprets the voltage sag as a weak signal and reduces transmit power, which cuts range. Run three full cycles — charge to completion, use the handset until the low-battery indicator shows, then recharge — and internal resistance drops to normal operating levels.