Coolpad Y91 Compatible Battery CPLD-380 3.8V 2500mAh

Coolpad Y91 / Fengshang 3 — 3.8V Li-Polymer Replacement Battery (CPLD-380)

This is a 3.8V, 2500mAh (9.5Wh) lithium-polymer battery for the Coolpad Y91, Fengshang 3, and Y803-9 smartphones. It replaces OEM part number CPLD-380. If your original cell has degraded, swollen, or failed entirely, this cell restores normal operation for calls, messaging, and apps.

• Y91, Fengshang 3, and Y803-9 compatibility: These three models share the same battery bay dimensions (79.20 × 61.50 × 3.20 mm), the same 3.8V nominal voltage rail, and the same CPLD-380 connector and BMS handshake — so one cell covers all three variants without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on Y91 hardware. The BMS accepted charge current correctly, protection circuitry triggered at expected low-voltage thresholds, and the fuel gauge IC read within normal calibration range across multiple cycles.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell — preventing erratic percentage readings from the start.

Sudden shutdown at 20–30% on the Coolpad Y91 after a cell swap

This happens because the fuel gauge IC on the Y91 is still calibrated to the discharge curve of the old, degraded cell. The new cell has a steeper voltage drop under modem and screen load than the IC expects at that state of charge. When voltage sags briefly below the shutdown threshold — even at a reported 25% — the phone cuts out. One full discharge cycle down to automatic power-off, followed by a full uninterrupted charge, resets the coulomb counter and clears the symptom.

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

Lithium-polymer cells self-discharge in storage, and if the cell dropped below approximately 2.5V per cell the BMS enters lockout mode to prevent damage — the phone will show no response at all, not even a charge indicator. Connect the phone to a wall charger (not a PC USB port, which may not supply enough current) and leave it untouched for 15–20 minutes. The BMS recovery circuit needs sustained input voltage to exit lockout before the phone will boot. If the charge LED comes on, the cell is recovering; let it reach at least 3.0V before attempting to power on.