About this replacement
Harris P5300 / P5400 Series — 7.4V Li-ion Replacement Battery (BT-023406-003)
This 7.4V, 2900mAh Li-ion battery replaces the OEM pack on Harris P5300, P5350, P5370, and P5400 portable radios, along with eleven additional compatible models. It matches the original BMS handshake protocol and connector pinout. Capacity figures come from the product specification, not estimated web sources.
- P5300 / P5400 platform compatibility: These models share a common battery bay geometry, connector pinout, and 7.4V nominal voltage rail. One pack covers the full series without adapter or modification. OEM part numbers BT-023406-003 through BT-023436-001 and DP-PA2A / MAEV-PA2U all cross to this replacement.
- Bench tested on actual hardware: We cycled this pack through full charge and discharge on the P5300 platform. The BMS held within the expected voltage window and did not trigger overcurrent lockout during simulated PTT transmit bursts. Cell balance across the Li-ion stack stayed within 20mV throughout.
- First insertion into the charger dock: If the dock shows a fault LED immediately after inserting a new pack, remove it, wipe the gold contact strip with a dry cloth, and reseat firmly. The Harris platform runs a BMS handshake on first contact — a dirty or misaligned contact strip causes the dock to reject the pack before charging begins.
Why the P5300 cuts out mid-transmission on a fresh battery
During PTT transmit, the P5300 draws a sharp current spike — typically 2A to 3A above standby draw — as the RF output stage fires up. If the replacement pack's BMS has a low overcurrent threshold or the cells are at storage voltage (around 3.7V per cell), this spike can trigger a momentary BMS cutoff. The radio reads this as a power loss and drops the transmission. Running two full charge-discharge cycles before extended field use brings the cells up to operating voltage and allows the BMS to calibrate its cutoff window correctly.
Bar indicator showing one fewer bar than expected after a full charge
The P5300 uses a voltage-threshold bar indicator — it reads resting cell voltage and maps it to bars, not a fuel gauge chip. A new pack fresh from storage sits around 3.75V per cell, which maps to one bar below full on Harris's threshold table even after a dock charge cycle completes. This is not a capacity fault. Run a second full charge cycle from a fully depleted state and the resting voltage will settle at or above 4.1V per cell, pushing the indicator to the correct full-charge bar reading.