Netlink i640 Cordless Phone Compatible Battery 3.6V 1100mAh

Netlink i640 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1100mAh Ni-MH replacement battery for the Netlink i640 cordless phone handset. It slots into the handset battery compartment and restores power to the unit when the original cell has degraded. Dimensions are 58.12 × 45.30 × 15.60mm — confirm these against your existing battery before ordering.

• Netlink i640 fit: The i640 runs a 3.6V Ni-MH cell with a fixed footprint. This battery matches that voltage rail and physical envelope, so the compartment door closes correctly and the contacts seat flush against the handset terminals.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a cordless phone test rig. The Ni-MH chemistry reached stable capacity after three full cycles, and the base station accepted the charge state without flagging an error.
• First charge on a new Ni-MH handset battery: After installing, place the handset in the base for a full 16 hours before first use. Ni-MH cells ship partially discharged from storage, and a slow first charge is what brings them to rated capacity — skipping this step is why many users report short talk time on new batteries.

Talk time shorter than the original battery after replacement

Ni-MH cells don't deliver full rated capacity from the first cycle. The chemistry needs three to five full charge-discharge cycles before the cell reaches 1100mAh. If talk time feels short in the first few days, run the handset down to low-battery warning, then return it to the base for a full charge. Repeat this three times and capacity will stabilise at the rated figure.

Base station showing no charge or error light after battery swap

Ni-MH batteries discharge slowly during storage and can arrive below the voltage threshold the base station expects before it begins a charge cycle. If the charge indicator stays off or shows an error, remove the handset, leave the battery out for 30 seconds, then reseat it firmly and return it to the base. If the base still won't accept the charge, try a different power outlet to rule out the base's own power supply before assuming the battery is at fault — the cell voltage at rest should read at least 3.0V across the terminals.