Radio Shack 23959 Cordless Phone Replacement Battery 3.6V 700mAh

Radio Shack 23959 / CLT2402 Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH rechargeable battery for Radio Shack cordless phone handsets. It fits the 23959, 432105, CLT2402, and 60AAAH3BJ22 among a wider range of compatible handsets. Capacity is rated at 2.52Wh — matching the original pack specification.

• Multi-model fit across the Radio Shack cordless range: These handsets share the same 3.6V three-cell Ni-MH configuration, connector pinout, and physical footprint. The BMS in each base station targets the same charge termination voltage, so one cell pack covers the full group.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a CLT2402 handset base. The base accepted the battery without error, charge termination fired correctly, and the BMS held the end-of-discharge cutoff at the expected threshold.
• First-charge protocol for Ni-MH handset packs: After installing, place the handset in the base for a full 16-hour charge before first use. Ni-MH cells shipped in storage state need a slow initial charge to reach rated capacity — skipping this step leaves you with noticeably shorter talk time on early cycles.

Talk time shorter than original battery after replacement

Ni-MH cells do not arrive at full capacity out of the box. Storage discharge and the electrochemical state of new cells both reduce usable capacity on early cycles. Expect cycles 1 through 5 to deliver less talk time than rated — this is normal conditioning behaviour, not a fault. By cycle 5, capacity stabilises near the 700mAh rating, assuming each cycle includes a full base-station charge.

Base station showing no charge light or error after swap

Base stations for DECT cordless phones check the incoming battery voltage before enabling the charge circuit. A pack that has dropped below roughly 3.0V during storage may sit below the base's acceptance threshold, so the charger never triggers. Remove the handset, wait 60 seconds, then reseat it firmly — contact pressure and a brief reset often allow the base to re-initialise the charge sequence. If the error persists, check that all three contact pins on the handset are clean and making solid contact with the base cradle.