About this replacement
Motorola XPR7350 / XPR3500 Series — 7.4V Li-ion Replacement Battery (PMNN4409)
This 7.4V, 2200mAh Li-ion battery replaces the PMNN4409 and its approved variants across the Motorola XPR7350, XPR3500, XPR3300, and XPR3000 series portable radios. It fits the same connector and BMS handshake profile as the factory pack. Voltage and capacity match the original spec exactly — 7.4V nominal, 16.28Wh.
- XPR7000e and XPR3000 series compatibility: These radio families share a common battery bay geometry, contact pin layout, and BMS communication protocol. One pack covers all listed models because Motorola standardised the battery interface across this platform generation.
- Bench tested on actual hardware: We ran this pack in an XPR7350 and cycled through PTT transmit bursts at full RF output. The BMS held voltage above the radio's low-power threshold throughout, and the charger dock accepted the handshake without fault on the first insertion.
- Contact strip care on first insertion: If the dock shows a fault LED on first seating, remove the pack and wipe the gold contact strip with a dry cloth. Reseat firmly. The XPR platform requires a clean contact cycle to complete the BMS handshake before charging begins — this is not a defect.
Why the XPR7350 drops to reduced TX power mid-shift on a new battery
New Li-ion cells ship at storage voltage — typically 3.6–3.7V per cell, not full charge. When the radio's RF amplifier draws peak current during a long PTT burst, a cell at storage voltage sags faster than a fully charged one. The XPR7350 interprets that sag as low battery and steps down transmit power to protect the circuit. A full charge cycle before field deployment eliminates this behaviour entirely.
Bar indicator showing one fewer bar than expected after inserting a new pack
The XPR series uses voltage-threshold bar indicators, not a fuel gauge chip. A new pack at storage voltage reads as partially depleted because the radio's thresholds are calibrated to a fully charged cell baseline. This is not a capacity fault. Charge the pack fully in the WPLN4232 or equivalent Motorola dock first — once cell voltage reaches 8.4V, the indicator will reflect actual charge state correctly.