About this replacement
Samsung Galaxy Mega 2 SM-G750 Series — 3.8V Li-ion Replacement Battery (EB-BG750BBC)
This is a 3.8V, 2500mAh (9.5Wh) Li-ion replacement battery for the Samsung Galaxy Mega 2. It fits SM-G750, SM-G750A, SM-G750F, SM-G7508, and additional SM-G750 variants. Use this when the original cell no longer holds adequate charge for normal daily use.
- SM-G750 variant compatibility: All SM-G750 variants share the same 3.8V voltage rail, the same EB-BG750BBC connector footprint, and the same BMS handshake with the Galaxy Mega 2's charge IC — so one cell covers the full model range without modification.
- Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the SM-G750 platform. The BMS negotiated correctly with the device's charge IC, and protection cutoffs triggered at expected thresholds under both idle and active screen load.
- First-cycle fuel gauge recalibration: On first use after installation, disable fast charging and run one full discharge-charge cycle from 100% down to automatic cutoff and back to full. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.
Sudden shutdown at 20–30% on the Galaxy Mega 2 after a cell swap
The Galaxy Mega 2's fuel gauge IC retains the discharge curve from the old cell after replacement. When the new cell hits a voltage cliff under modem or display load, the IC hasn't yet learned where that cliff sits — so the phone cuts out even though the percentage shown looks safe. One complete discharge-charge cycle with fast charging disabled forces the coulomb counter to rebuild its model against the new cell. After that cycle, the reported percentage tracks actual cell voltage accurately.
Galaxy Mega 2 not powering on after sitting in storage with a new battery installed
Li-ion cells stored below 2.5V per cell trigger a BMS deep-discharge lockout — the battery refuses to output current as a protection measure. The SM-G750 won't boot from this state because the board never receives enough voltage to initialise. Connect the device to a wall charger, not a PC USB port, and leave it for 15–20 minutes without pressing the power button. The charger's constant-voltage trickle will bring the cell above the BMS recovery threshold, after which normal charging resumes — verify the charging indicator appears on screen before disconnecting.