G-SHOT G512 Replacement Battery BLI-248 3.7V 1000mAh

G-SHOT G512 / G515 — 3.7V Li-ion Replacement Battery (BLI-248)

This is a 3.7V, 1000mAh Li-ion replacement battery for the G-SHOT G512 and G515 smartphones. It replaces OEM part BLI-248 and fits the physical cell bay on both models. Capacity is 1000mAh (3.7Wh) — matching the stock specification.

• G512 and G515 compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — that is why one cell covers both. The 52.95 × 33.07 × 8.01mm footprint seats flush in either chassis without modification.
• Bench tested on actual hardware: We cycled this cell through charge, load, and cutoff on the bench. The BMS triggered low-voltage cutoff at the correct threshold and accepted a standard charge current without error flags on the charge IC.
• 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 into an uncalibrated state — preventing erratic percentage readings from the first charge onward.

Why the G512 reports wrong battery percentage after a cell swap

The G512 uses a fuel gauge IC that tracks charge state via a coulomb counter calibrated against the original cell's discharge curve. Swap the cell and the IC is now measuring a new curve against old reference data. The percentage display drifts — often reading 40% when the cell is closer to 15%. One full discharge to automatic power-off, followed by a complete charge to 100% without interruption, forces the IC to rewrite its reference curve against the new cell. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the modem or display triggers a current spike the cell cannot sustain at that state of charge — voltage drops below the BMS cutoff threshold even though the gauge still shows capacity remaining. It is a voltage-cliff issue, not a capacity defect. A full recalibration cycle resets the coulomb counter so the OS knows where the real cutoff voltage sits. If shutdowns persist after one full cycle, check that the cell connector is fully seated — a partial connection raises internal resistance and pulls the voltage cliff higher.