TeXet TX-D7400 Replacement Battery 2.4V 600mAh Ni-MH

TeXet DECT TX-D7400 / TX-D7750 — 2.4V Ni-MH Replacement Battery (5M702BMX)

This is a 2.4V, 600mAh Ni-MH replacement battery for the TeXet DECT TX-D7400 and TX-D7750 cordless phone handsets. It replaces OEM part numbers 5M702BMX, GP0827, GP0845, GP0735, GP0747, and GP0748. Install it when the original pack no longer holds enough charge to keep the handset usable between trips to the base.

• TX-D7400 and TX-D7750 compatibility: Both handsets share the same 2.4V two-cell NiMH pack format, connector pinout, and physical footprint — 35.40 × 32.50 × 6.70mm. One replacement covers both models without modification.
• Bench tested on actual hardware: We cycled this pack on the TX-D7400 handset. The BMS accepted charge from the base station immediately, and the cell voltage stabilised correctly across three full discharge-and-charge cycles.
• First charge after installation: Seat the handset in the base and leave it for a full 16 hours before the first call. NiMH cells ship partially discharged. Skipping this slow initial charge leaves the pack below rated capacity and the first few cycles feel short — this is chemistry, not a fault.

Talk time shorter than the original battery after replacement

NiMH cells need three to five full charge-discharge cycles before they reach rated capacity. The electrodes haven't fully activated from factory storage, so the first few cycles deliver noticeably less talk time than the original worn battery — and far less than the 600mAh rating. Run the handset until it prompts a low battery warning, then return it to the base for a full charge. By cycle four or five, capacity settles at or near the rated 600mAh.

Base station shows no charge light or error light after fitting the new pack

NiMH packs can drop below 2.0V during long storage. Some DECT base stations won't initiate a charge cycle if the incoming voltage is too low — the base reads it as a fault rather than a flat battery. Remove the handset, leave the pack connected, and let it sit in the base for 30 minutes. Most bases have a trickle pre-charge that raises the cell voltage enough to trigger the main charge cycle. If the light remains off after 30 minutes, check the base contacts are clean and making firm contact with the handset terminals.