Wisycom MPRLBP Replacement Battery 3.7V 1500mAh

Wisycom MPR50-IEM / MPR30-ENG Series — 3.7V Li-ion Replacement Battery (MPRLBP)

This 3.7V 1500mAh Li-ion cell replaces the original MPRLBP battery in the Wisycom MPR50-IEM wireless in-ear monitor receiver and related Wisycom portable units. It fits the MPR50-IEM, MPR30-ENG, MTP60, and MPR50-IFB, among others. Capacity figures come from the product data — 5.55Wh per cell.

• MPR50-IEM, MPR30-ENG, MTP60 and MPR50-IFB platform: These units share the same MPRLBP cell format, connector pinout, and BMS handshake protocol. The receiver's power management IC authenticates the pack on insertion — same voltage rail, same communication line across all four models.
• Bench tested on actual hardware: We cycled this cell on a Wisycom-compatible test rig, running the BMS through charge, standby, and active RF draw. The protection circuit responded correctly to over-current and end-of-discharge thresholds, and the receiver logged the pack without error on first insertion.
• First-cycle BMS logging on the MPR50-IEM: Before your first use on stage, seat the receiver in its charging dock and run one complete charge cycle uninterrupted. The MPR50-IEM's power management firmware registers the new cell's internal resistance profile during that first full charge — skipping it means the battery gauge reads inaccurately until the cycle completes.

Why the MPR50-IEM receiver cuts out mid-transmission on a fresh pack

The MPR50-IEM draws current from two loads simultaneously — the UHF receive circuit and the audio output stage feeding the IEM driver. Under peak combined draw, a new cell at storage voltage (typically 3.6–3.7V) can sag below the BMS cutoff threshold momentarily. This looks like a dropout rather than a dead battery. The fix is a full charge cycle before use, which brings the cell to 4.2V and gives the BMS enough headroom to handle the combined peak draw without tripping.

Receiver shows charged but audio cuts after a few minutes of use

This symptom points to a cell sitting at storage voltage while the dock's charge indicator reads full — a mismatch between the dock's charge-complete signal and the actual cell state. The dock terminates charge based on current drop, but a cell shipped at storage voltage can trigger that threshold early. Remove the battery, reinsert it, and run a second full charge cycle from scratch. If the receiver's gauge then climbs past 4.1V and holds, the cell is correctly logged and the symptom will not return.