Samsung SCH-411 Replacement Battery BTL1061EB 3.7V 1200mAh

Samsung SCH-411 / SGH-410 Series — 3.7V Li-ion Replacement Battery (BTL1061EB)

This is a 3.7V, 1200mAh Li-ion replacement battery for the Samsung SCH-411, SGH-410, SCH-2500, and S410 feature phones. It replaces OEM part number BTL1061EB. The original cells in these phones are now well over a decade old, and capacity loss is the primary reason these devices stop holding a charge.

• SCH-411 / SGH-410 family fit: These models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. One cell format covers the whole group — no adapter or modification needed.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the SCH-411 platform. The BMS accepted charge from the handset's onboard charge IC without error, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first install: After fitting this cell, let the phone discharge to automatic shutdown, then charge uninterrupted to 100% before use. The SCH-411's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle resets it to the new cell's characteristics so percentage readings stay accurate.

Why the SCH-411 shows wrong battery percentage after a cell swap

The fuel gauge IC in these Samsung feature phones tracks capacity using a coulomb counter that was trained on the original cell's internal resistance and discharge profile. A new cell has a different impedance curve, so the counter's reference points are off from the first charge. The phone may show 40% and shut down, or sit at 100% longer than expected. One full discharge-to-shutdown and uninterrupted recharge cycle resets the counter baseline to the new cell.

Phone shuts off suddenly at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity issue. Under load — an active call or backlight at full brightness — the cell's terminal voltage drops sharply, crossing the low-voltage cutoff threshold even though the displayed percentage still reads mid-range. The fuel gauge IC hasn't recalibrated yet, so it misreports remaining charge. Run one full discharge cycle to let the gauge relearn the new cell's voltage-to-capacity curve, and the shutdowns stop. If they continue after two full cycles, check that the battery contacts in the bay are clean and making firm contact.