About this replacement
Compustar Pro RFX T2 Series — 3.7V Li-Polymer Replacement Battery (JHY442027)
This is a 3.7V, 150mAh Li-Polymer battery for the Compustar Pro RFX T2 wireless remote transmitter. It fits the Pro RFX T2, Pro RFX-P2WT12, RFX-P2WT12-SS, and P2WT11-SS remotes, along with additional models in the same family. When the original cell loses charge capacity, this replacement restores full remote start and keyless entry function.
- Pro RFX platform compatibility: These remotes share the same compact Li-Polymer cell format, 3.7V supply rail, and JHY442027 footprint across the lineup. The BMS on each unit uses the same charge termination logic, so one cell spec covers the full group without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Pro RFX platform and confirmed the BMS accepted charge termination cleanly at 4.2V, with no false over-voltage flags or cutoff errors during draw.
- Re-sync after power interruption: Swapping the battery cuts power to the remote's memory. The Pro RFX T2 requires a programming sequence to re-pair with the control module — follow the Compustar sync procedure specific to your installed firmware version before testing range.
Remote start not activating after battery swap
Replacing the battery clears the remote's stored pairing data. The control module no longer recognises the transmitter until the sync sequence is completed. On most Compustar Pro RFX installations, this means entering the module's programming mode via the vehicle's ignition cycle and pressing the remote button within the pairing window. Check your installer's configuration sheet for the exact step count — sequence length varies by firmware.
Reduced transmission range in the first few uses
A fresh Li-Polymer cell ships at storage voltage, typically around 3.6V — below the 3.7V nominal operating point. At that voltage, transmit power from the RF module is slightly reduced, which shortens effective range. After two or three full charge cycles, the cell reaches stable operating voltage and range returns to normal. Charge the remote fully before testing range — measure improvement after the second full charge, not the first.