About this replacement
Crosscall Trekker M1 — 3.8V Li-Polymer Replacement Battery (LPN38300)
This is a 3.8V, 2900mAh Li-Polymer battery for the Crosscall Trekker M1 rugged smartphone. It replaces OEM part number LPN38300 when the original cell has degraded and can no longer hold a usable charge. Dimensions are 70.58 × 50.00 × 5.60mm — confirm these against your original before fitting.
- Trekker M1 fit: The M1 uses a fixed 3.8V nominal Li-Polymer cell with a specific footprint and connector pinout tied to the phone's charge IC and BMS handshake. This cell matches that exact configuration — voltage rail, physical dimensions, and connector orientation.
- Bench tested on actual hardware: We ran charge and discharge cycles on this cell against the Trekker M1 charge IC. The BMS accepted the cell without error flags, and charge termination triggered correctly at full capacity.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell.
Why the Trekker M1 reports the wrong battery percentage after a cell swap
The Trekker M1 uses a fuel gauge IC that builds a discharge model from the cell it has been running. When you install a new cell, the IC still references the old cell's coulomb-counting data. This causes the percentage readout to be inaccurate — often reading higher or lower than the actual state of charge. One full discharge down to auto-shutdown followed by a full uninterrupted charge resets the coulomb counter and aligns the gauge to the new cell's curve. After that cycle, percentage readings stabilise.
Sudden shutdown at 20–30% on the replacement cell
This happens when the fuel gauge IC is still calibrated to the worn-out original cell, which had a flatter voltage curve near depletion. The new cell has a steeper voltage drop at the same state of charge, so under modem or screen load the voltage momentarily dips below the protection threshold before the gauge reads zero. The phone shuts off to protect the cell even though the display shows charge remaining. Run one full discharge-charge cycle — the fuel gauge recalibrates and the shutdowns stop once it tracks the new cell's actual voltage cliff, typically around 3.4–3.5V under load.