SCP-41LBPS Kyocera Milano Replacement Battery 3.7V 1400mAh

Kyocera Milano / C5120 / C5121 — 3.7V Li-ion Replacement Battery (SCP-41LBPS)

This is a 3.7V, 1400mAh Li-ion cell for the Kyocera Milano, C5120, and C5121 smartphones. It replaces part numbers SCP-41LBPS and SCP-42LBPS. If your original cell has swollen, fails to hold a charge, or causes random shutdowns, this is the direct swap.

• Milano, C5120, and C5121 compatibility: These three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 65.20 × 44.00 × 5.10mm cell fits without modification, and the charge IC communicates with the same fuel gauge logic across all three variants.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on a C5120 unit. The BMS accepted charge from both USB and wall adapter without tripping an overcurrent fault. Cell voltage held within spec through screen-on and modem-active load cycles.
• Fuel gauge recalibration after installation: On first use, disable fast charging and run one complete discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the phone's fuel gauge IC a clean reference curve for the new cell before high-current charging begins.

Why the Milano reports wrong battery percentage after a cell swap

The Kyocera Milano uses a coulomb-counting fuel gauge IC that builds its capacity model against discharge data from the original cell. When a new cell goes in, that stored model no longer matches the actual discharge curve. The phone reads voltage and translates it using the old calibration, so the percentage shown can be off by 10–20%. One full discharge-to-shutdown followed by a complete uninterrupted charge resets the IC's reference points. After that cycle, percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity problem. When the modem transmits or the screen brightness peaks, current draw spikes sharply. If the cell's internal impedance is slightly higher than the original — common in a new cell before it has been cycled — voltage briefly drops below the BMS cutoff threshold, and the phone shuts down even though the fuel gauge still shows charge remaining. Run two to three full discharge-charge cycles to condition the cell and reduce internal impedance. After conditioning, the BMS cutoff should not trigger above 3.4V under normal load.