BT ON AIR 1000 Executive Replacement Battery 3.6V 400mAh

BT ON AIR 1000 Executive Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 400mAh Ni-MH replacement battery for BT cordless handsets in the ON AIR Executive and Classic range. It fits the ON AIR 1000 Executive, 1100 Executive, 1250 Classic, and 1300 Executive. The battery slots into the handset compartment and powers the DECT radio and speaker circuitry during untethered use.

• ON AIR 1000 / 1100 / 1250 / 1300 compatibility: These models share the same 3.6V single-cell NiMH power rail, identical connector orientation, and matching physical footprint — 49.60 x 33.62 x 6.70mm — so one battery type covers all four handsets without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on NiMH-compatible test equipment. The cell voltage held steady through the charge curve and the protection circuit responded correctly at both ends of the voltage window.
• First-charge protocol for NiMH cordless handsets: After installing, seat the handset in the base station and leave it for a full 16 hours before first use. NiMH cells in cordless phones need this slow initial charge to reach rated capacity — skipping it means the first few charge cycles will feel shorter than expected.

Talk time shorter than the original battery after replacement

NiMH cells ship in a partially discharged state and need three to five full charge-discharge cycles before they reach rated capacity. The battery is not faulty — the chemistry requires cycling to activate full cell capacity. Each full charge followed by normal use brings performance closer to the rated 400mAh. After five cycles, talk time should match or exceed the original worn-out pack.

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

A new NiMH battery stored for several months can arrive at a voltage low enough that the base station's charge controller does not recognise it as a valid pack. The base expects to see a cell voltage above its acceptance threshold before it starts the charge cycle. Place the handset in the base, wait five minutes, then remove and reseat it firmly — this resets the contact detection on most BT ON AIR bases. If the charge light still does not appear, check that the handset is fully seated and the base contacts are clean and free of oxidation.