About this replacement
LG K22 2020 — 3.85V Li-Polymer Replacement Battery (BL-M03)
This 3.85V, 2800mAh Li-Polymer cell replaces the OEM BL-M03 battery in the LG K22 2020 smartphone. It fits LMK200BMW, K200BMW, LMK200BAW, and related K22 variants. Swap it when the original cell no longer holds a charge or triggers unexpected shutdowns during normal use.
- K22 2020 platform compatibility: The LMK200-series devices all share the same 3.85V battery bay, connector pinout, and BMS handshake protocol. BL-M03 and EAC64791001 are interchangeable OEM references for the same cell specification across these variants.
- Bench tested on actual hardware: We cycled this cell through charge-discharge on the K22 platform and confirmed the BMS accepted the handshake without fault codes. The protection circuit triggered correctly at low-voltage cutoff and current spiked within spec on fast-charge initiation.
- Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — preventing erratic percentage readings from the start.
Sudden shutdown at 20–30% on the replacement cell
The LG K22's fuel gauge IC was calibrated against the original cell's internal resistance profile. When a new cell goes in, the IC still uses the old discharge curve, which means it misjudges how much voltage the cell can sustain under modem and display load. At around 20–30% reported charge, the cell voltage drops below the cutoff threshold faster than the gauge predicted, and the phone shuts off. One full discharge-to-shutdown followed by a full charge resets the coulomb counter and syncs the gauge to the new cell. After that cycle, shutdowns at high reported percentages typically stop.
USB-PD fast charge not accepted on first cycle after swap
Some K22 units don't negotiate fast charge on the first cycle with a new BL-M03 cell because the charge IC reads the new cell's higher initial impedance as a fault condition and falls back to standard 5V charging. This isn't a defective battery — it's the charge controller being conservative with an uncalibrated cell. Let the phone complete one full slow charge before attempting fast charge again. After that first cycle the impedance reading normalises and fast charge resumes without further intervention.