About this replacement
Samsung Galaxy S8 — 3.85V Li-Polymer Replacement Battery (EB-BG950ABE)
This 3.85V, 2600mAh Li-Polymer cell replaces the original battery in the Samsung Galaxy S8 and its regional variants, including the SM-G950F, SM-G950U1, and Galaxy S8 TD-LTE. It matches OEM part numbers EB-BG950ABE, GH43-04731A, and EB-BG950ABA. Swap it in when the original cell can no longer hold voltage under screen or modem load.
- SM-G950 variant coverage: The SM-G950 series shares a single battery bay geometry, connector pinout, and BMS handshake across all regional builds — F, U1, TD-LTE, and the base Galaxy S8. One cell fits the full line because Samsung locked the voltage rail and connector spec across those SKUs at the platform level.
- Bench tested on actual hardware: We ran this cell on an SM-G950F. The BMS accepted the cell on first boot, charge IC engaged normally, and the protection circuit tripped correctly at the low-voltage cutoff threshold during a deliberate drain test.
- Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and let the phone run through one complete discharge-charge cycle on standard charging. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current fast charging pushes amps into an uncalibrated coulomb counter.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff issue, not a capacity problem. Under sudden high loads — the modem hitting LTE band transitions or the screen peaking at full brightness — the cell voltage drops sharply. If the BMS sees voltage fall below its cutoff threshold, it kills the rail immediately, even when the reported percentage looks safe. The fuel gauge IC is still reading a calibration curve from the old cell, so the percentage shown and the actual cell state diverge. Run one full discharge down to automatic shutdown, then charge uninterrupted to 100% to let the coulomb counter reset against the new cell.
USB-PD fast charge not working on the first cycle after swap
The Galaxy S8 uses Samsung's Adaptive Fast Charging protocol, which requires a handshake between the charge IC and the BMS before high-current charging is allowed. On a freshly installed cell, the BMS may not complete that handshake on the first plug-in — the phone charges at standard 5V instead of stepping up to the fast-charge voltage. This is not a fault with the cell. Unplug, wait 10 seconds, and reconnect. If the charger still does not step up, complete the first full calibration cycle at standard charge rate first, then retest with the original Samsung fast charger at 9V/1.67A.