Avant Apollo Cordless Phone Replacement Battery 3.6V 600mAh

Avant Apollo — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 600mAh Ni-MH rechargeable battery for the Avant Apollo cordless phone handset. It fits directly into the handset battery compartment and restores power to units where the original pack no longer holds charge. Voltage and cell count match the Apollo's charging circuit exactly.

• Apollo handset fit: The Apollo uses a single 3.6V NiMH cell pack with a specific footprint — 42.45 x 29.77 x 14.37mm. This battery matches that form factor and the base station's charge acceptance threshold, so the handset seats and charges without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on NiMH-compatible test equipment. The BMS held stable at 3.6V nominal and accepted trickle charge correctly from a simulated base station input — no false full-charge trip on the first cycle.
• First charge on the Apollo base: After installing, place the handset in the base and leave it for a full 16 hours before first use. NiMH cells in cordless phones need a slow initial charge to reach rated capacity — cutting it short means the first several cycles will show noticeably shorter talk time 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. On the first cycle, you may see noticeably less talk time than the original battery delivered at its best. This is normal cell behaviour, not a fault. Run the handset until the low-battery indicator triggers, return it to the base for a full charge, and repeat — capacity increases with each cycle.

Base station showing no charge or error light after battery swap

A NiMH pack that has sat in storage can drop below the voltage threshold the base station uses to confirm a valid battery is present. When voltage is too low, some base units interpret it as a fault rather than a flat pack and display an error light instead of charging. Remove the handset, wait 10 seconds, and reseat it firmly — this resets the charge detection cycle. If the error persists, connect the handset to the base and leave it undisturbed for 30 minutes; the base should detect the rising cell voltage and switch to normal charge mode at around 3.0V.