Topcom Cocoon 300 Compatible Battery 3.6V 700mAh

Topcom Cocoon 300 / 350 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH replacement battery for the Topcom Cocoon 300 and Cocoon 350 cordless DECT phones. It slots into the handset and restores power when the original cell has degraded beyond useful capacity. Dimensions are 45.90 × 31.20 × 10.70mm — confirm these against your existing pack before ordering.

• Cocoon 300 and 350 compatibility: Both handsets share the same 3.6V single-cell NiMH form factor, connector orientation, and physical envelope. One pack covers both models without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a NiMH-compatible analyser. The cell accepted a full charge without voltage anomalies and the protection circuit held within spec across all test cycles.
• First-charge conditioning for NiMH cordless packs: After installing, seat the handset in the base station and leave it for a full 16 hours before first use. NiMH cells arrive partially discharged from storage. Skipping the slow first charge shortens the usable capacity you get from every subsequent cycle.

Range dropping on the Cocoon 300 after a battery swap

NiMH cells sag under RF transmit load — the handset draws a short current spike every time it communicates with the base station. If the replacement pack hasn't been fully conditioned, its internal resistance is higher than rated, and voltage dips under that load. The DECT radio reduces transmit power when supply voltage falls, which cuts effective range. Run three to five full charge-discharge cycles through the base station before judging range performance.

Base station charge light not coming on after fitting new battery

NiMH cells that have sat in storage can drop below 3.0V. Some cordless base stations won't initiate a charge cycle if the incoming voltage is too low — the charger circuit reads it as a fault rather than a depleted cell. Remove the handset, wait 30 seconds, then reseat it firmly so the contacts close properly. If the charge light still won't activate, the cell voltage may need a brief top-up via a standalone NiMH charger set to 3.6V before the base will take over.