Casio PMG3345 Cordless Phone Compatible Battery 3.6V 600mAh

Casio PMG3345 — 3.6V Ni-MH Replacement Battery

This 3.6V, 600mAh Ni-MH battery replaces the rechargeable pack in the Casio PMG3345 cordless phone handset. It restores power to handsets that no longer hold charge through a full call or standby period. Physical dimensions are 40.00 x 42.00 x 13.50mm — confirm your original battery matches before fitting.

• PMG3345 handset fit: The Casio PMG3345 uses a single-cell 3.6V Ni-MH pack with a specific footprint. This battery matches that voltage rail and form factor, so the handset cover closes correctly and the charge contacts align with the base station cradle.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a Ni-MH test rig. The cell accepted a full charge without thermal runaway and held voltage above the handset's low-battery cutoff through multiple discharge passes.
• First-charge protocol for Ni-MH handsets: After installing, seat the handset in the base cradle and leave it for a full 16 hours before the first use. Ni-MH cells in cordless phones need that slow initial charge to reach rated capacity — skipping it can leave you with noticeably shorter talk time from day one.

Base station showing no charge light after fitting a new Ni-MH pack

Ni-MH batteries sitting in storage lose voltage over time. If the cell arrives below roughly 3.0V, some cordless base stations won't initiate a charge cycle — they see the pack as faulty rather than flat. The fix is to leave the handset seated in the base undisturbed for at least 30 minutes. Most base station chargers will eventually detect the cell and begin trickle charging, after which the normal charge indicator activates.

Talk time shorter than expected after the first few uses

Ni-MH cells don't deliver full rated capacity straight out of the box. The first three to five charge-discharge cycles are conditioning cycles — each one allows the cell chemistry to reach closer to its 600mAh rating. If talk time feels short after the first charge, run the handset down until it signals low battery, then return it to the base for a full charge. Repeat this three to five times and capacity will stabilise near rated output.