About this replacement
Motorola MTP600 / MTP3000 Series — 3.7V Li-ion Replacement Battery
This 3.7V, 1650mAh Li-ion battery fits the Motorola MTP600, MTP3000, MTP3100, and MTP3150 portable land mobile radios, along with eight additional MTP-series variants. It matches the original pack's connector pinout, housing dimensions, and BMS communication protocol. No OEM part number is published for this platform, but the physical and electrical spec match has been confirmed against production units.
- MTP600 and MTP3000 series compatibility: These models share a common battery bay geometry, three-pin connector layout, and BMS handshake voltage. One pack covers the full listed range without adapter or modification.
- Bench tested on actual hardware: We cycled this pack through full charge, PTT transmit load, and rest discharge on MTP3100 hardware. The BMS held cutoff at the correct low-voltage threshold and responded normally to the dock's charge-initiation signal.
- First-insertion contact check: If the charger dock shows a fault LED on first insertion, remove the battery, wipe the gold contact strip with a dry cloth, and reseat firmly. The MTP platform requires a clean contact cycle before the dock accepts the new BMS handshake and begins charging.
Why the MTP600 cuts out mid-transmission on a freshly inserted pack
The MTP600 draws a sharp current spike the moment PTT is pressed — transmit current can exceed the steady-state draw by a factor of three or more. A new cell shipped at storage voltage sits around 3.6–3.7V, which is close enough to the BMS low-voltage cutoff that a sudden TX load can pull the terminal voltage below the trip threshold. The BMS interprets this as an unsafe condition and cuts the output. One full charge cycle brings the cell to 4.2V and gives the BMS adequate headroom to absorb the transmit spike without tripping.
Bar indicator showing one fewer bar than expected after fitting a new pack
The MTP series uses simple voltage-threshold bar indicators — each bar corresponds to a voltage band, not a calculated percentage. A new cell at storage voltage reads in the lower band and displays fewer bars, which looks like a faulty or underspec pack but is not. Charge the battery fully in the dock until the LED goes solid green, then reinsert. The indicator will show the correct level once the cell is at full charge voltage.