Sanyo SY5LEB Replacement Battery 3.7V 750mAh

Sanyo SCP-5000 / SCP-5100 / SCP-5150 — 3.7V Li-ion Replacement Battery (SY5LEB)

This is a 3.7V, 750mAh (2.78Wh) lithium-ion battery for the Sanyo SCP-5000, SCP-5100, and SCP-5150 candybar-style phones. It replaces OEM part number SY5LEB and installs directly into the original battery bay. If your phone shuts down unexpectedly or refuses to hold a charge, this is the correct cell for those models.

• SCP-5000, SCP-5100, and SCP-5150 compatibility: All three models share the same battery bay dimensions, connector pinout, and 3.7V voltage rail. One cell covers all three — no variation in BMS handshake or physical format between them.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SCP platform and confirmed the BMS accepted charge current without fault flags. Voltage held steady across the full discharge curve with no premature cutoff.
• Fuel gauge recalibration on first use: After installing this cell, run one complete discharge to low battery warning, then charge uninterrupted to 100% before normal use. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle resets that baseline against the new cell.

Why the SCP-5000 reports wrong battery percentage after a cell swap

The SCP-5000 uses a fuel gauge IC that tracks capacity 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 new cell's actual voltage profile. The gauge reads from an outdated reference and can show 40% when the cell is actually near cutoff voltage. One full discharge-charge cycle lets the IC relearn the new cell's curve and restore accurate percentage readings.

Sudden shutdown at 20–30% on the replacement cell

This happens when the display or radio briefly pulls more current than the cell can sustain at that state of charge, causing the cell voltage to sag below the BMS cutoff threshold — typically around 3.0V — even though the gauge still shows charge remaining. The phone reads available voltage, not stored capacity, so the shutdown can look like a surprise. Confirm the shutdown is happening at low-but-not-zero percentages, then complete two full discharge-charge cycles to let the fuel gauge IC map the cell's real voltage cliff. After calibration, the gauge flags low battery before the BMS trips.