CECT S1 Replacement Battery ELF0160 3.7V 1100mAh Li-ion

CECT S1 — 3.7V Li-ion Replacement Battery (ELF0160)

This is a 3.7V, 1100mAh Li-ion replacement battery for the CECT S1 smartphone. It carries OEM part number ELF0160 and slots directly into the S1's battery bay. Capacity is 4.07Wh — matching the original cell specification.

• CECT S1 fitment: The S1 uses a compact 51.53 x 37.36 x 5.35mm cell cavity with a fixed connector orientation. This battery matches those physical dimensions and the 3.7V nominal voltage rail the phone's power management IC expects. A mismatch in cell height alone can stress the rear cover and break the connector tab.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the S1 platform. The BMS accepted the charge handshake without error flags, held voltage above 3.5V through the mid-discharge range, and tripped cutoff cleanly at the low-voltage threshold — no thermal events observed.
• Fuel gauge recalibration on first install: After fitting this battery, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before resuming normal use. The S1's fuel gauge IC is calibrated against the old cell's discharge curve — one full cycle resets the coulomb counter to the new cell's actual capacity.

Sudden shutdown at 20–30% on the CECT S1 after a cell swap

This happens because the fuel gauge IC still holds the discharge curve of the degraded original cell. When the new cell's voltage drops under modem or screen load, the phone sees a voltage that maps to near-zero on the old curve and shuts down — even though charge remains. The fix is a full calibration cycle: drain the phone to auto-shutdown, then charge to 100% in one uninterrupted session. After that cycle, the coulomb counter resets and percentage readings stabilise.

CECT S1 not powering on after the battery sat in storage

Li-ion cells self-discharge in storage. If this battery dropped below approximately 2.5V per cell during a long shelf period, the BMS enters lockout mode to prevent damage — and the phone shows no response at all. Connect the phone to a charger and leave it for 15–20 minutes without pressing the power button. The charge IC needs time to trickle current into the cell and lift voltage above the BMS re-enable threshold before a normal boot sequence can start.