About this replacement
LG Velvet 5G / G900 Series — 3.85V Li-Polymer Replacement Battery (BL-T50)
This is a 3.85V, 4000mAh Li-Polymer replacement battery for the LG Velvet 5G and G900 series smartphones, including the G900V, G900T, and LMG900TM. It replaces OEM part numbers BL-T50 and EAC64790201. This cell powers the display, processor, and 5G modem stack directly.
- G900 series compatibility: The G900V, G900T, and LMG900TM share the same battery bay geometry, connector pinout, and BMS handshake protocol as the base Velvet 5G. All variants run the same 3.85V nominal rail, so one cell covers the full lineup without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a G900-series unit. The BMS accepted the cell on first connect, charge termination triggered correctly at 4.35V, and the fuel gauge IC began tracking capacity within the first cycle.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes amps into an uncalibrated state — which causes erratic percentage readings.
Sudden shutdown at 20–30% on the Velvet 5G after a cell swap
The Velvet 5G's 5G modem draws sharp current spikes during band switching and handoff events. If the fuel gauge IC is still calibrated to the old degraded cell's discharge curve, it misreads remaining capacity on the new cell. The phone's software acts on that stale data and triggers a low-voltage shutdown even though the actual cell voltage hasn't dropped dangerously. Run one full discharge to around 3.0V at the terminals, then a full uninterrupted charge to let the coulomb counter reset against the new cell.
USB-PD fast charge not activating on the first charge after replacement
After a cell swap, the charge IC sometimes defaults to trickle mode on the first cycle because it treats the new cell as potentially over-discharged or unverified. This is a protective handshake — not a fault in the replacement cell. Plug into the original LG fast charger rather than a third-party USB-PD brick for the first charge. Once the charge IC confirms the cell is stable above 3.0V per cell, it re-enables the fast charge negotiation on subsequent cycles.