Sanyo 23621 Cordless Phone Compatible Battery 3.6V 700mAh

Sanyo 23621 / CL-410 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH battery pack for Panasonic cordless DECT phones, including the 23621, CL-410, 3N-600AA(mtm), and GES-PCF02 among others. It replaces a dead or degraded handset battery that no longer holds a charge. Slot it into the handset battery compartment and return the phone to service.

• Compatible handset models: These models share the same 3.6V three-cell NiMH pack format, connector pin-out, and physical footprint. The base station charges at a fixed trickle rate matched to this voltage and chemistry, so swapping chemistry or voltage would break the charge cycle.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a DECT handset platform. The BMS accepted charge from the base station cradle without error, and voltage held within the expected window across the full discharge curve.
• First-install charge requirement: After installing, seat the handset in the base for a full 16-hour charge before first use. NiMH cordless phone batteries shipped in a partial state of charge need that slow first cycle to reach rated capacity — skipping it means the first few calls drain the pack faster than expected.

Talk time shorter than original battery after replacement

NiMH cells need three to five full charge-discharge cycles before they hit rated capacity. A new pack out of the box will underperform compared to a broken-in original. Each full cycle conditions the cell chemistry and raises the usable capacity incrementally. By cycle five, the pack should be delivering close to the rated 700mAh.

Base station showing no charge light after new pack installed

NiMH batteries stored in a warehouse can drop to a voltage level that some base stations treat as a fault condition rather than a depleted pack. The base expects to see a voltage above roughly 3.0V before it begins the charge cycle. If the charge indicator stays off, remove the handset, wait 30 seconds, and re-seat it firmly — this resets the charge detection circuit. If the light still does not come on, check that the battery contacts in the handset are clean and making full contact.