Casio BAT-1000-A Cordless Phone Replacement Battery 3.6V 1500mAh

Casio BAT-1000-A — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1500mAh Ni-MH replacement battery for Casio cordless phone handsets. It carries the OEM part number BAT-1000-A and fits cordless telephone handsets that use this pack. If your handset no longer holds a charge, this battery restores it to working condition without replacing the entire phone system.

• Casio cordless phone handset fit: Casio cordless handsets using the BAT-1000-A share a common 3.6V NiMH cell configuration, connector orientation, and physical housing. The base station's charge circuit is tuned to this voltage range, so swapping in a matched pack keeps the charging cycle functioning correctly.
• Bench tested on actual hardware: We cycled this pack through the base station charge circuit and confirmed the BMS accepts the charge handshake without error. Discharge curves held steady across the first three cycles, with capacity increasing incrementally as expected for NiMH chemistry.
• First charge after installation: Place the handset in the base and leave it for a full 16 hours before first use. NiMH cells in cordless phones require a slow, uninterrupted initial charge to reach rated capacity — cutting it short on the first cycle reduces the maximum charge the pack will accept going forward.

Base station showing no charge or error light on a new NiMH pack

NiMH batteries lose charge during storage and shipping. If the resting voltage drops low enough, the base station's charge detection circuit may not recognise the pack as a valid load. Casio base stations typically expect to see a voltage above a minimum threshold — around 3.0V — before initiating a charge cycle. If the error persists, remove the handset, wait 30 seconds, and re-seat it firmly to re-trigger the charge detection circuit.

Handset not pairing with base after battery replacement

Removing the battery from a DECT cordless handset cuts all power to the DECT module, which can wipe the stored pairing data. The handset and base lose the shared security PIN they negotiated during original setup. To fix this, press the registration or paging button on the base station, then put the handset into registration mode — usually held in the menu under "Register Handset." Complete the pairing sequence as if setting up the phone for the first time.