About this replacement
Samsung Galaxy Grand 3 / SM-G7200 — 3.8V Li-ion Replacement Battery (EB-BG720CBC)
This is a 3.8V, 2200mAh Li-ion replacement battery for the Samsung Galaxy Grand 3 and Galaxy Grand 3 Duos. It fits SM-G720AX, SM-G7200, and related variants. It slots into the same compartment as the original EB-BG720CBC and EB-BG720CBK cells.
- Grand 3 and Grand 3 Duos platform fit: Both single-SIM and Duos variants run the same 3.8V battery rail with identical connector pinout and BMS handshake — one cell covers the entire SM-G720 range without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an SM-G7200 unit. The BMS accepted charge without interruption, voltage held steady under display and modem load, and no thermal events occurred at the charge IC.
- Fuel gauge recalibration on first use: Disable fast charging for the first full discharge-charge cycle after installation. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes into an uncalibrated profile.
Sudden shutdown at 20–30% on the Grand 3 after a cell swap
The Grand 3's fuel gauge IC still holds the discharge curve from the old, degraded cell. When the new cell's voltage drops below that stale curve at 20–30% reported charge, the IC signals a shutdown before the cell is actually depleted. This is a calibration mismatch, not a faulty replacement. Run one full uninterrupted discharge to automatic shutoff, then charge to 100% without interruption — the coulomb counter resets against the new cell's actual capacity and the phantom shutoffs stop.
OS reporting wrong battery percentage after installation
Samsung's fuel gauge IC on the SM-G720 platform uses a stored charge curve to estimate remaining capacity. Swapping the physical cell doesn't reset that curve — the IC keeps comparing live voltage against data built on a different cell's behaviour. Reported percentage can jump, plateau, or read 100% while the phone is clearly draining. One complete discharge-to-shutoff followed by a full uninterrupted charge cycle forces the IC to recalibrate its coulomb counter against the replacement cell's actual curve.