About this replacement
PHICOMM Freecomm 2S — 3.8V Li-Polymer Replacement Battery (BL-F34)
This is a 3.8V, 2800mAh Li-Polymer replacement battery for the PHICOMM Freecomm 2S and F680L smartphones. It uses OEM part number BL-F34 and fits directly into either model. Capacity is 10.64Wh — matching the original cell specification.
- Freecomm 2S and F680L compatibility: Both models share the same BL-F34 battery footprint, voltage rail, and connector pinout. The BMS handshake is identical across both, so one cell fits either device without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Freecomm 2S platform. The BMS accepted the charge curve without cutoff errors, and voltage held steady under screen and modem load.
- First-cycle fast charge caution: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.
Sudden shutdown at 20–30% on the Freecomm 2S after a cell swap
This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a voltage cliff under combined modem and display load before the gauge reaches 0%. The phone interprets the voltage drop as an emergency cutoff and shuts down, even though the gauge still shows charge remaining. Running one full discharge-to-shutdown cycle followed by a full charge resets the coulomb counter and eliminates most premature cutoffs.
Phone reports wrong battery percentage after the BL-F34 is installed
The fuel gauge IC stores a learned discharge profile from the original cell. A new cell with a different internal impedance shifts the voltage-to-capacity curve, so the reported percentage drifts — often reading 100% for too long, then dropping sharply. The fix is straightforward: drain the phone to automatic shutdown, then charge uninterrupted to 100% without disconnecting. After one complete cycle the coulomb counter recalibrates to the new cell and percentage reporting stabilises.