Telrad 3040 Cordless Phone Replacement Battery 3.6V 700mAh

Telrad 3040 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH battery for the Telrad 3040 cordless telephone handset. It replaces the original cell when the handset no longer holds charge or drops calls due to voltage sag. Dimensions are 45.00 × 31.10 × 10.50mm — confirm against your current cell before ordering.

• Telrad 3040 handset fit: The 3040 handset runs a single-cell 3.6V Ni-MH pack at this exact footprint. The connector orientation and cell dimensions match the original bay, so no modification is needed to seat the pack.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Ni-MH-compatible test rig. The cell accepted a full charge without thermal runaway and held voltage above 3.3V through the discharge curve.
• First-charge conditioning on Ni-MH handsets: After installing, place the handset in the base for a full 16-hour charge before first use. Ni-MH cells in cordless phones are shipped in a partially discharged state. Skipping this step leaves capacity on the table for the first several cycles.

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

Ni-MH cells stored for months can drop below 3.0V. Some Telrad base stations look for a minimum voltage on the charge contacts before starting the charge cycle — if the cell arrives too depleted, the base reads it as absent or faulty and shows no charge indicator. The fix is a brief trickle charge using a standalone Ni-MH charger to bring the cell above the acceptance threshold. Once the pack reaches approximately 3.2V, reseat the handset in the base and the charge light should activate normally.

Talk time shorter than expected after the first few charges

Ni-MH cells do not deliver rated capacity from cycle one. The 700mAh rating is reached after three to five full charge-discharge cycles — this is normal electrochemical behaviour, not a defect. Each full cycle builds crystalline structure in the cell and increases usable capacity incrementally. Run three complete discharge-and-recharge cycles with the handset used until it prompts a low-battery warning, then returned to the base for a full charge.