Samsung SGH-X830 Replacement Battery 3.7V 700mAh ABGX8307BE

Samsung SGH-X830 / SGH-X838 — 3.7V Li-ion Replacement Battery (ABGX8307BE)

This 3.7V 700mAh Li-ion battery replaces the original cell in the Samsung SGH-X830 and SGH-X838 mobile phones. Both handsets use the same battery footprint, connector, and BMS communication protocol, so one part number covers both models. Capacity is 700mAh (2.59Wh), matching OEM spec.

• SGH-X830 and SGH-X838 compatibility: Both models share the same battery bay dimensions (59.81 × 29.99 × 7.84mm), identical connector pinout, and the same BMS handshake. Either OEM part number — ABGX8307BE or ABGX8307WE — covers both handsets.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SGH-X830 platform. The BMS accepted the cell without error flags, charge termination triggered correctly at 4.2V, and low-voltage cutoff engaged at the expected threshold.
• Fuel gauge recalibration on first use: Disable any fast-charge mode for the first full discharge-to-charge cycle after installation. The fuel gauge IC on these handsets is calibrated to the old cell's discharge curve. One complete cycle at standard current lets the coulomb counter relearn the new cell before higher charge rates are applied.

Why the SGH-X830 reports wrong battery percentage after a cell swap

The SGH-X830 uses a fuel gauge IC that tracks charge state by counting coulombs against a stored discharge curve from the original cell. When you install a new cell, that stored curve no longer matches the actual cell chemistry, so the reported percentage drifts — often reading higher than reality early in the cycle. The fix is one full discharge from 100% down to automatic cutoff, followed by a full charge to 4.2V at standard rate. After that single cycle, the fuel gauge resets its reference and percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC is still running the old cell's discharge curve after a swap. The old curve may have mapped 20% as a safe operating region, but the new cell hits a voltage cliff at that state of charge under the load of an active call or screen-on event. The phone's protection circuit cuts power before the OS gets a low-battery warning. Perform one full discharge-charge cycle at standard rate — once the fuel gauge recalibrates to the new cell, the cutoff point shifts and the premature shutdown stops.