About this replacement
Samsung SGH-F400 / GT-M7500 Series — 3.7V Li-ion Replacement Battery (AB463651BE)
This is a 3.7V, 950mAh Li-ion replacement battery for the Samsung SGH-F400 and compatible models including the SGH-F408 and GT-M7500 Emporio Armani. It replaces OEM part numbers AB463651BE, AB463651BEC, AB463651BU, and AB463651BC. Slot it into any device on the fit list and the phone powers on as expected.
- SGH-F400 and GT-M7500 platform fit: These models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. The BMS handshake requirements across this group are identical, so one cell covers all of them without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the SGH-F400. The BMS accepted charge current from the first cycle, protection cutoffs triggered correctly at both ends of the voltage range, and the phone did not flag any battery warnings.
- Fuel gauge recalibration on first use: Disable fast charging for the first complete discharge-charge cycle after fitting this battery. The fuel gauge IC on these phones calibrates its discharge curve during that first cycle. Running a high current into an uncalibrated cell causes the percentage readout to drift and can trigger premature low-battery warnings on subsequent cycles.
Sudden shutdown at 20–30% on the SGH-F400
This shutdown pattern is a voltage cliff issue, not a capacity fault. Under peak load — screen on, active call, or data transfer — the cell voltage drops sharply below the BMS cutoff threshold even though the fuel gauge still reads 20–30%. An aged or storage-depleted cell has higher internal resistance, so voltage sags faster under load than the coulomb counter predicts. After one full recalibration cycle, the fuel gauge IC aligns its model to the actual discharge curve of the new cell, and the shutdowns stop. If they continue past two full cycles, check that the battery connector pins are fully seated and making clean contact.
Phone will not power on after the battery sat in storage
Li-ion cells that self-discharge below approximately 2.5V per cell trigger a BMS lockout — the protection circuit cuts output to prevent damage, and the phone will not respond to the power button. Connect the phone to a charger and leave it for 15–20 minutes before pressing power. The charge IC trickle-charges the cell back above the BMS re-enable threshold, which sits around 2.8–3.0V, at which point the circuit resets and the phone will boot normally. If the screen shows no charging indicator after 20 minutes on charge, try a different cable — a high-resistance connection may not be delivering enough current to wake the BMS.