V Tech iS6200 Replacement Battery BT290576 3.7V 140mAh

V Tech iS6200 — 3.7V Li-ion Replacement Battery (BT290576)

This is a 3.7V 140mAh Li-ion replacement cell for the V Tech iS6200 wireless DECT headset. It replaces OEM part BT290576 and slots directly into the headset housing. Fit the new cell when the original no longer holds a charge or the headset cuts off unexpectedly mid-call.

• iS6200 platform fit: The iS6200 headset uses a single Li-ion cell at 3.7V nominal with a compact 35.60 × 24.65 × 10.00mm footprint. The BMS on this replacement matches the charge profile and cutoff thresholds the base station expects from the OEM pack.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the iS6200 base station. The BMS handshake completed cleanly, charge termination triggered at the correct voltage, and the base station reported a full charge without error.
• First-cycle base station registration: On first use, seat the headset in the base and let it complete a full uninterrupted charge before taking a call. DECT headsets log the new cell during that first cycle — skipping it causes the talk-time indicator to read inaccurately until the cell is properly registered.

Base station not recognising the new pack after fitting

The iS6200 base station communicates with the battery's BMS to verify cell state before beginning a charge cycle. If the replacement cell ships at storage voltage — typically around 3.6V — the base may flag a charge error or show no activity on the indicator. This is not a fault with the cell. Seat the headset firmly in the cradle and leave it undisturbed for at least 30 minutes. The BMS will initialise and the base station will begin a normal charge cycle.

Headset cuts out mid-call even with a charged battery

The iS6200 draws current for both audio processing and the DECT radio simultaneously during a call. If the cell has degraded, that combined load causes a brief voltage sag below the BMS cutoff threshold, which shuts the headset off even though the indicator showed a full charge. A new cell resolves this because its internal resistance is low enough to sustain the combined draw without sagging. After fitting the replacement, confirm the resting voltage is at or above 3.7V before the first call.