Radio Shack 43-1106 Cordless Phone Replacement Battery 3.6V 700mAh

Radio Shack 43-1106 — 3.6V Ni-MH Replacement Battery (ET-1106)

This is a 3.6V 700mAh Ni-MH replacement battery for Radio Shack cordless handsets that take part number 43-1106 or ET-1106. It fits the original battery slot and connects to the same charging circuit the base station expects. Swap it in when the original pack no longer holds a charge or the handset dies faster than it used to.

• 43-1106 and ET-1106 cross-reference: Both part numbers refer to the same 3.6V single-cell NiMH pack used across Radio Shack cordless handsets. The cell count, terminal spacing, and connector orientation match the original, so the base station's charging circuit sees no difference.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a NiMH-compatible test rig. The BMS accepted charge from a standard 3.6V trickle circuit without triggering a voltage rejection error, and cell balance held across five full cycles.
• First-charge protocol for NiMH cordless handsets: After installing, seat the handset in the base for a continuous 16-hour charge before first use. NiMH cells in cordless phones need this slow initial charge to reach rated capacity — skipping it leaves the pack conditioning short and talk time below spec for the first several cycles.

Base station showing no charge or error light after battery swap

A NiMH pack that has sat in storage can drop to a voltage the base station's charge controller reads as a fault rather than a dischargeable cell. Most Radio Shack base stations expect to see at least 3.0V across the pack before they begin trickle charging. If the pack shipped below that threshold, the base may flash an error light or simply not charge. Place the handset in the base, leave it undisturbed for 30 minutes, then check again — the controller will usually retry and accept the pack once it detects a small rise in terminal voltage.

Talk time shorter than the original battery for the first few uses

NiMH cells do not deliver full rated capacity straight out of the box. The 700mAh rating is reached after three to five full charge-and-discharge cycles, not on the first use. Each cycle lets the cell chemistry stabilise and the BMS calibrate its cutoff points. Run the handset until the low-battery warning sounds, return it to the base for a full charge, and repeat — talk time will increase noticeably by the third cycle.