GP T111 4.8V Cordless Phone Replacement Battery 1300mAh Ni-MH

GP T111 — 4.8V Ni-MH 1300mAh Replacement Battery (T111 / 70AAS4BMU)

This is a 4.8V, 1300mAh Ni-MH battery pack for GP cordless phone handsets. It replaces the original T111 and 70AAS4BMU packs used in compatible DECT cordless phone models. When the original pack degrades and no longer holds a charge, this swap restores handset function without replacing the phone.

• T111 and 70AAS4BMU compatibility: These two part numbers reference the same 4.8V, 4-cell Ni-MH pack format. The cell arrangement, connector pitch, and voltage rail all match the handset's charging circuit, so the base station charges this pack the same way it did the original.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a DECT handset platform. The BMS accepted charge from a standard base station cradle without triggering error states, and voltage held stable under RF transmit load.
• First-charge conditioning for Ni-MH packs: After installing, seat the handset in the base for a full 16 hours before first use. Ni-MH cells ship partially discharged. Skipping this slow first charge cuts into usable capacity from cycle one and takes several additional cycles to recover.

Base station showing no charge or error light after swap

Ni-MH packs discharged below roughly 3.8V total during storage can sit outside the base station's acceptance window. The charger circuit checks incoming voltage before starting a charge cycle, and a pack that reads too low gets flagged rather than charged. Most DECT bases will recover the pack if you place the handset in the cradle and leave it undisturbed for at least 30 minutes — the trickle pre-charge stage brings voltage up to the acceptance threshold. If the error clears, continue the full 16-hour first charge before using the handset.

Range drops noticeably after a few months of use

Reduced range on a DECT handset is often a battery voltage problem, not a signal problem. When Ni-MH cells age or haven't been properly conditioned, voltage sags under the transmit power draw, and the handset's RF output drops in response. The result is shorter effective range even though the phone shows a charge indicator. Running three to five full charge-and-use cycles through the pack — fully charging, then using until the handset signals low battery — lets the cells reach rated capacity and keeps voltage stable under RF load.