ZTE WP650 Ni-MH Replacement Battery 3.6V 700mAh

ZTE WP650 / WP850 — 3.6V Ni-MH Replacement Battery (Ni3607T30P3S473211)

This is a 3.6V, 700mAh Ni-MH rechargeable battery for the ZTE WP650 and WP850 cordless phone handsets. It replaces OEM part Ni3607T30P3S473211 directly. The battery sits inside the handset and powers both the DECT radio and the speaker circuit.

• WP650 and WP850 compatibility: Both handsets run off the same 3.6V Ni-MH cell with an identical connector and footprint. The BMS on each base station accepts the same charge termination voltage, so one part number covers both models.
• Bench tested on actual hardware: We cycled this cell through the WP650 base station and confirmed the charge circuit recognised the pack, reached delta-V cutoff correctly, and held resting voltage at 3.9V after a full charge.
• First charge on a NiMH cordless handset: After installing, seat the handset in the base and leave it for a full 16 hours before taking your first call. NiMH cells ship partially discharged and need a slow first charge to reach the 700mAh rated capacity — cutting it short locks in a lower ceiling from the start.

Base station showing no charge light after fitting a new NiMH pack

NiMH batteries lose voltage during storage. If the pack drops below roughly 3.0V, some base stations refuse to initiate a charge cycle because the voltage sits outside the expected acceptance window. The base interprets a deeply discharged cell the same way it would a shorted or missing pack. To recover it, hold the handset firmly in the cradle for 10–15 minutes — most ZTE bases will attempt a trickle pre-charge at low current before switching to full charge once the cell reads above the threshold. If the light still does not activate, check the cradle contacts with a dry cloth and reseat the handset.

Talk time shorter than the original battery after replacement

This is expected behaviour with fresh NiMH cells and is not a fault. NiMH chemistry takes three to five full charge-and-use cycles before the cell reaches rated capacity. On the first cycle, you may see noticeably shorter talk sessions. Each subsequent full cycle conditions the cell further. After five complete cycles — full charge, then use until the handset gives a low-battery warning — capacity should stabilise at or close to the rated 700mAh. Do not judge the battery until cycle three at the earliest.