Radio Shack 23-479 Cordless Phone Replacement Battery 3.6V 700mAh

Radio Shack 23-479 / 2300479 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH rechargeable battery for the Radio Shack cordless phone models 23-479 and 2300479. It replaces the original handset battery when the phone no longer holds a charge or stops working away from the base. Capacity is rated at 700mAh (2.52Wh), matching the original specification.

• 23-479 and 2300479 handset fit: Both model numbers reference the same handset platform. They share an identical battery bay, connector orientation, and cell voltage requirement — a single 3.6V Ni-MH pack fits both without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a cordless phone test rig. The BMS accepted full charge from a standard base station, held voltage within spec across the discharge curve, and showed no false low-battery flags during testing.
• First-charge conditioning for Ni-MH handsets: Place the handset in the base for a full 16-hour charge before first use. Ni-MH cells in cordless phone packs ship partially discharged and need a slow initial charge to reach rated 700mAh capacity — skipping this step will result in noticeably shorter talk time from the start.

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

A Ni-MH battery that has sat in storage can drop to a voltage low enough that the base station's charge controller does not recognise it as a valid pack. The base station checks for a minimum cell voltage before enabling the charge circuit — if the pack reads too low, the charge indicator stays off and nothing happens. Place the handset in the base for at least 30 minutes regardless of the indicator; most base stations will begin a trickle charge that brings the pack up to acceptance voltage. If the light still does not come on after an hour, remove the handset, wait 10 seconds, and re-seat it firmly — this resets the charge detection cycle.

Range dropping noticeably mid-call after battery swap

Reduced range after a battery swap usually points to voltage sag under RF transmit load, not a faulty battery. When a Ni-MH pack has not been fully conditioned, its internal resistance is higher than rated — under the burst current draw of the DECT transmitter, voltage dips and the handset pulls back transmit power to protect the circuit. Run three to five full charge and discharge cycles through normal use to bring internal resistance down to rated levels. After conditioning, check that the battery contacts in the handset bay are clean and making firm contact — oxidised contacts add resistance and produce the same symptom.