Mobistel Cynus F10 Compatible Battery 3.8V 2300mAh

Mobistel Cynus F10 — 3.8V Li-Polymer Replacement Battery

This 3.8V, 2300mAh lithium-polymer cell is a direct replacement for the Mobistel Cynus F10 smartphone. It matches the original battery's voltage, capacity, and physical footprint — 78.90 × 57.64 × 3.60 mm — so it seats correctly in the battery bay without modification. Replace it when the original cell can no longer hold a charge or shuts the phone down unexpectedly.

• Cynus F10 fit: The F10 uses a sealed battery bay with a specific connector orientation and a fuel gauge IC that communicates charge state to Android. This cell matches that connector and the BMS protocol the phone expects, so the OS can read charge data correctly from cycle one.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench, confirming BMS handshake, charge termination at 4.35V, and stable voltage delivery under simulated screen and modem load without premature cutoff.
• First-cycle fuel gauge reset: After fitting this cell, disable fast charging and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins, so Android reports accurate percentages from the start.

Sudden shutdown at 20–30% on the Cynus F10

This happens when a degraded cell can no longer sustain voltage under the combined load of the modem radio and display backlight. At around 3.6V under load, the cell voltage collapses faster than the fuel gauge IC tracks it, and the phone interprets that as a hard cutoff condition. A fresh cell with healthy internal resistance handles that load spike without the voltage cliff. If you see this on a new replacement cell in the first two cycles, run a full discharge to 0% reported charge, then charge uninterrupted to 100% — the fuel gauge IC needs that full-range calibration cycle.

Phone won't power on after the replacement battery sat in storage

Li-polymer cells self-discharge during storage, and if the cell drops below roughly 2.5V, the BMS enters a lockout state to prevent damage — the phone will show nothing when you press the power button. Connect the phone to a wall charger, not a computer USB port, and leave it for 20–30 minutes without pressing any button. The charger's trickle current slowly brings the cell above the BMS re-enable threshold, typically around 2.8–3.0V, after which the BMS releases and normal charging resumes.