Swisscom TOP S600 Cordless Phone Compatible Battery 3.7V 750mAh

Swisscom TOP S600 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 750mAh Li-ion battery for the Swisscom TOP S600 cordless DECT handset. It replaces the original cell when the handset no longer holds a charge through a normal day of use. Dimensions are 50.20 × 37.50 × 7.65mm — confirm these against your existing cell before ordering.

• TOP S600 handset fit: The TOP S600 runs a single-cell 3.7V Li-ion pack with a low-current draw profile typical of DECT standby and voice transmission. The connector pinout and physical footprint match the OEM cell directly.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a DECT handset platform. The BMS held the charge curve within spec and showed no false low-battery flags at the handset display.
• First-charge protocol for Li-ion DECT handsets: Seat the handset in the base immediately after installing this battery and leave it for a full uninterrupted charge before first use. Li-ion cells in low-draw cordless handsets calibrate the fuel gauge during that initial charge — skipping it causes the battery indicator to read inaccurately from day one.

Talk time shorter than the original battery after fitting the replacement

A fresh Li-ion cell ships at partial state of charge — typically 30–50%. The handset's fuel gauge reads that as a near-empty cell and throttles the reported capacity accordingly. Run two or three full charge-discharge cycles and the gauge recalibrates to the actual 750mAh capacity. If talk time is still short after three cycles, check that the base station charging contacts are clean and making solid contact with the handset terminals.

Handset loses DECT pairing after battery replacement

Removing the battery completely cuts power to the handset's volatile memory, which can erase the stored base station registration on some DECT models. The handset will power on but show no base connection or a searching icon. To fix this, run the pairing sequence from the base station menu — on most Swisscom bases, hold the registration button on the base for three seconds, then confirm pairing on the handset within 60 seconds.