AB553446BE Samsung SGH-F318 Replacement Battery 3.7V 650mAh

Samsung SGH-F318 / GT-B2100 Series — 3.7V Li-ion Replacement Battery (AB553446BE)

This is a 3.7V, 650mAh Li-ion replacement battery for the Samsung SGH-F318, GT-B2100, GT-B2100 Solid Extreme, SGH-F310, and compatible models. It matches the original AB553446BE spec and fits the same compact battery bay without modification. Capacity is 650mAh (2.41Wh) — identical to the factory cell this replaces.

• SGH-F318 and GT-B2100 compatibility: These models share the same AB553446BE footprint, voltage rail, and connector pinout. The BMS handshake between the phone's charge IC and this cell matches the original — no firmware flags or charge rejection on pairing.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on the SGH-F318 platform. The BMS held cutoff cleanly at 3.0V under load and accepted charge without thermal events or current spikes above spec.
• Fuel gauge recalibration on first use: After fitting this battery, run one complete discharge down to auto-shutoff, then charge uninterrupted to 100% before normal use. The phone's fuel gauge IC is calibrated to the old cell's discharge curve — skipping this step causes erratic percentage readings from the first charge onward.

Sudden shutdown at 20–30% on the GT-B2100 and SGH-F318

The GT-B2100 is rated for outdoor and wet conditions, which means its backlight and radio draw harder than a standard feature phone. Under that load, an aged or mismatched cell hits a voltage cliff — typically around 3.55V — before the fuel gauge registers empty. The phone's processor sees voltage drop below its brown-out threshold and cuts power immediately, even though the displayed percentage still reads 20–30%. A fresh 650mAh cell with low internal impedance keeps voltage above 3.6V under the same load, eliminating the cliff. After fitting this battery, complete one full discharge cycle so the fuel gauge IC remaps its curve to the new cell.

Phone shows incorrect battery percentage after cell replacement

Samsung's fuel gauge IC on these mid-2000s feature phones uses a stored discharge curve built up over the life of the original cell. When a new cell goes in, that stored curve no longer matches the actual charge state of the replacement. The result is percentage readings that jump, stall, or read full when the cell is not. This is not a fault with the replacement — it is the coulomb counter recalibrating. Discharge the phone fully to auto-shutoff, then charge it to 100% in a single uninterrupted session to reset the reference curve.