About this replacement
Ritron Jobcom JMX Series — 7.2V Ni-MH Replacement Battery (BPJ-6N)
This is a 7.2V 1500mAh Ni-MH replacement battery for Ritron Jobcom portable two-way radios. It fits the JMX-100, JMX-150, and JMX-450 models using OEM part numbers BPJ-6N, BPJ-6N-SC, and GPHC132M05. Voltage and capacity match OEM spec exactly.
- JMX-100, JMX-150, JMX-450 compatibility: These three Jobcom variants share the same 7.2V six-cell Ni-MH pack format, identical connector pinout, and the same BMS handshake voltage window — so one replacement battery covers all three without modification.
- Bench tested on actual hardware: We ran this pack through a full charge-discharge cycle on the Jobcom dock. The BMS accepted the handshake on first insertion, and charge current stepped down correctly at the top-of-charge threshold with no fault LED.
- First-cycle contact check on the Jobcom 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 Jobcom dock requires a clean contact to complete its BMS handshake before charge current begins.
Why the Jobcom cuts out mid-transmission on a freshly inserted battery
Ni-MH cells ship at storage voltage — typically 1.0–1.1V per cell, which puts a six-cell 7.2V pack around 6.0–6.6V on arrival. The Jobcom's transmit circuit draws a sharp current spike when PTT is pressed. At storage voltage, internal cell impedance causes a voltage dip that triggers the radio's undervoltage cutoff before the pack has been conditioned. This is not a fault — it is the BMS protecting the radio from a sustained low-voltage transmit state. Run one full charge cycle on the dock before first use in the field.
Bar indicator showing one fewer bar than expected after charging
The Jobcom uses a simple voltage-threshold bar display — each bar corresponds to a fixed voltage step across the pack. A new Ni-MH cell can take two to three full charge-discharge cycles before it reaches peak capacity and holds voltage under load. After the first charge, resting voltage may read high, but the display drops a bar as soon as PTT load pulls the pack down. Run two full cycles through the dock and the bar reading will stabilise at the correct level for the pack's actual charge state.