About this replacement
Motorola R7 / R7A — 7.4V Li-ion Replacement Battery (PMNN4807)
This 7.4V 2600mAh Li-ion battery replaces the PMNN4807 series pack in the Motorola R7 and R7A portable two-way radios. It fits professional radio users in security, business, and emergency services who need a direct swap when their original pack no longer holds charge. Voltage and capacity match the OEM specification exactly.
- R7 and R7A compatibility: Both models run the same 7.4V rail and use an identical physical connector with the same BMS handshake protocol — one pack covers both variants without modification.
- Bench tested on actual hardware: We ran this pack through the R7 dock cycle and confirmed the BMS negotiates correctly with the charger, holds the charge curve without cutoff, and delivers full voltage at the transmit contact under PTT load.
- First insertion into the charger dock: If the dock shows a fault LED on first insertion, remove the battery, wipe the gold contact strip with a dry cloth, and reseat firmly — the R7 platform requires a clean contact cycle to accept the new BMS handshake before charging begins.
Why the R7 cuts out mid-transmission on a freshly inserted battery
New cells ship at storage voltage — typically around 3.7V per cell, giving roughly 7.4V pack voltage total. When PTT is pressed, the radio draws a sharp current spike to power the RF output stage. If the pack hasn't completed at least one full charge cycle, the BMS may read that spike as an overcurrent event and trip the protection circuit, cutting audio mid-transmission. A full charge before first use clears this — the BMS resets its overcurrent threshold once the cells have reached rated capacity and the impedance drops to normal operating range.
Bar indicator showing one fewer bar than expected after fitting this pack
The R7 uses a voltage-threshold bar indicator — each bar corresponds to a voltage band, not a percentage from a fuel gauge chip. A new pack at storage voltage sits in a lower threshold band than a fully charged cell, so the radio displays fewer bars immediately after fitting. This is not a fault with the cell. Charge the pack fully, and the indicator will reflect the correct voltage band once the pack reaches 8.3–8.4V at full charge.