Rocketfish RF-MAB2 Compatible Battery 3.7V 300mAh

ROCKETFISH RF-MAB2 / RF-MAB2-T — 3.7V Li-Polymer Replacement Battery (ICP5/25/25)

This 3.7V, 300mAh lithium-polymer cell replaces the original battery in the ROCKETFISH RF-MAB2 and RF-MAB2-T wireless headsets. It powers both the audio playback and DECT radio transmission simultaneously. Capacity figure is from the product specification — 300mAh / 1.11Wh.

• RF-MAB2 and RF-MAB2-T fit: Both headset variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol — 26.91 x 25.80 x 5.00 mm cell, same voltage rail, same charge termination logic. One cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the RF-MAB2 base station. The BMS completed handshake correctly, charge termination triggered at the right cutoff, and the protection circuit responded normally to load from the combined audio and radio draw.
• First-cycle base station logging: Place the headset in the base station for a complete uninterrupted charge cycle before making any calls. DECT headsets log the new cell's capacity during that first cycle — skipping it causes the talk-time estimate to read inaccurately for several sessions.

Why the RF-MAB2 cuts out mid-call on a new battery

The RF-MAB2 runs audio decoding and the DECT radio transmitter off the same cell simultaneously. That combined draw creates short current spikes that can trip the BMS protection circuit if the cell hasn't been through a proper conditioning cycle. A cell sitting at storage voltage — around 3.7V — has not yet been characterised by the base station's charge controller. Run two to three full charge-discharge cycles through the base station before extended use, and the cut-outs typically stop.

Base station showing a charging error after fitting the new cell

The RF-MAB2 base station reads a small identification signal from the battery's protection circuit before it begins charging. If the headset was stored or shipped with the cell at a low voltage, the base may not detect that signal and will flag an error instead of starting a charge. Remove the headset from the base, wait 10 seconds, then reseat it firmly — the connector needs full contact for the BMS handshake to complete. If the error persists, check that the cell voltage hasn't dropped below 3.0V, which is the recovery threshold for this chemistry.