Swisscom Aton CL306 Replacement Battery 3.6V 400mAh

Swisscom Aton CL306 — 3.6V Ni-MH Replacement Battery

This 3.6V 400mAh Ni-MH battery fits the Swisscom Aton CL306 and CL-306 cordless handset. It replaces the original rechargeable cell that sits inside the handset and powers calls and standby operation. Capacity is 400mAh (1.44Wh), matching the original specification.

• CL306 and CL-306 fitment: Both model codes refer to the same Swisscom Aton handset platform. The battery shares the same voltage rail, physical footprint (48.30 × 33.41 × 6.65mm), and connector orientation, so it seats correctly in the battery compartment without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge passes on a DECT handset platform at 3.6V. The NiMH chemistry accepted a full charge without voltage anomalies, and standby current draw held within the expected range for this class of handset.
• First charge on the CL306: After installing, place the handset in the base cradle for a full 16-hour charge before use. NiMH cells shipped in storage-discharged state need a slow initial charge to reach rated capacity — skipping this step will leave the battery underperforming from day one.

Talk time shorter than original battery after replacement

NiMH cells typically need three to five full charge and discharge cycles before reaching their rated 400mAh capacity. A new battery used straight from the box will often feel weaker than the original — this is normal chemistry, not a faulty cell. Each time you drain the handset and return it to the base for a full charge, usable capacity increases. By cycle five, the battery should be delivering its full rated performance.

Base station showing no-charge or error light after swap

Swisscom Aton base stations check the incoming voltage from the handset battery before initiating a charge cycle. A NiMH cell that has self-discharged in storage may arrive below the threshold the base expects, causing it to show a fault light or refuse to charge. Remove the handset, wait 10 seconds, then reseat it firmly in the cradle. If the error persists, the cell may need a short external boost charge to lift voltage above 3.0V before the base will recognise it.