Sennheiser BA 62 SK 6212 Replacement Battery 3.7V 1100mAh

Sennheiser SK 6212 / LM 6062 — 3.7V Li-Polymer Replacement Battery (BA 62 / 508517)

This is a 3.7V, 1100mAh Li-Polymer replacement for the original BA 62 battery. It fits the Sennheiser SK 6212 bodypack wireless transmitter, the LM 6062 lavalier module, and the L 6000 charging unit ecosystem. Swap it in when the original cell no longer holds a charge through a full performance or broadcast session.

• SK 6212 and LM 6062 compatibility: Both the SK 6212 bodypack and the LM 6062 share the same BA 62 form factor, connector pinout, and voltage rail. The L 6000 charger reads the cell through the same contact strip, so the BMS handshake runs identically across all three devices.
• Bench tested on actual hardware: We cycled this cell through an L 6000 charger and monitored BMS communication. The charger recognised the pack on first insertion, completed a full charge cycle without error flags, and the SK 6212 transmitted cleanly under combined audio and RF draw.
• First cycle in the L 6000 charger: Seat the new battery in the L 6000 and run one complete charge cycle before using it in the SK 6212. The L 6000 logs the new cell during that first cycle — until it does, the transmitter's fuel gauge will read inaccurately and may show a false full-charge state.

Why the SK 6212 drops signal mid-transmission on a new battery

The SK 6212 runs two simultaneous loads: the audio circuit and the UHF transmitter. Under peak RF output, combined current draw spikes sharply. If the replacement cell hasn't completed a full conditioning cycle, its internal resistance is still elevated — the BMS sees a momentary voltage sag and cuts the output to protect the cell. After three to five full charge-discharge cycles, internal resistance drops and the sag narrows. Most mid-transmission dropouts on a new pack clear themselves by cycle four.

L 6000 showing a charging error after inserting the new pack

The L 6000 uses a contact-based BMS handshake to verify the pack before charging begins. If the battery has been stored at low voltage — below roughly 3.0V — the charger's detection circuit may flag it as a fault rather than attempt a charge. Remove the pack, wait ten seconds, and reseat it firmly so all three contacts engage flush. If the error persists, the cell voltage is likely too low for the standard charge entry point — use a Li-Po recovery charger to bring it above 3.1V first, then transfer back to the L 6000.