British Telecom Verve 410 Replacement Battery 2.4V 600mAh

British Telecom Verve 410 / Verve 450 — 2.4V Ni-MH Replacement Battery (5M702BMXZ)

This is a 2.4V 600mAh Ni-MH rechargeable battery for the British Telecom Verve 410 and Verve 450 cordless handsets. It replaces OEM part 5M702BMXZ and fits directly into the battery compartment on both models. The cell dimensions are 35.40 × 32.50 × 6.70mm.

• Verve 410 and 450 compatibility: Both handsets share the same battery bay dimensions, connector polarity, and 2.4V charging circuit. A single cell format covers both models without modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a DECT handset base station. The NiMH pack accepted charge normally, the base station indicator moved to full charge status, and voltage held steady under RF transmit load.
• First charge on a NiMH cordless handset: After fitting, place the handset in the base and leave it for a full 16 hours before first use. NiMH cells arrive from storage partially discharged, and the slow first charge lets the pack reach its rated 600mAh capacity properly.

Talk time shorter than expected after fitting a new NiMH pack

NiMH cells do not reach full rated capacity on the first cycle. The chemistry requires three to five full charge-discharge cycles before the cell stabilises at 600mAh. Until then, talk time will be noticeably shorter than the original battery at its best. Run the handset down fully, return it to the base for a complete charge, and repeat — capacity increases with each cycle.

Base station charge light not activating after battery swap

A NiMH pack that has sat in storage can drop below the voltage threshold the base station uses to detect a valid cell. If the base shows no charge activity or an error light, the handset is likely reading the low resting voltage as a fault. Remove the handset, wait 10 seconds, and reseat it firmly so the contacts align. If the base still does not respond, check the resting voltage across the battery terminals — it should read at least 2.0V to trigger normal charging.