Coolpad 5218S Replacement Battery 3.7V 1500mAh CPLD-113

Coolpad 5218S / 7236 / 5218D — 3.7V Li-ion Replacement Battery (CPLD-113)

The CPLD-113 is a 3.7V, 1500mAh Li-ion cell that fits the Coolpad 5218S, 7236, and 5218D smartphones. It restores normal calling, messaging, and app functionality when the original cell has degraded or failed to hold a charge. Dimensions are 58.00 × 52.00 × 4.70mm — confirm clearance before fitting.

• 5218S, 7236, and 5218D compatibility: These three Coolpad models share the same battery bay geometry, voltage rail, and connector pinout, which is why one cell covers all three. The BMS handshake protocol is identical across the range, so no firmware difference affects charge acceptance.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the 5218S platform. The BMS accepted charge without cutoff events, and voltage held steady above 3.5V through the bulk of the discharge curve.
• Fuel gauge recalibration on first cycle: On first use after installation, run one complete discharge down to auto-shutoff, then charge to 100% uninterrupted. This lets the coulomb counter IC re-anchor its endpoints to the new cell before the OS starts reporting state-of-charge figures you can trust.

Sudden shutdown at 20–30% on the replacement cell

The Coolpad 5218S fuel gauge IC stores a discharge curve calibrated to the old cell. When a new cell with a slightly different internal resistance is installed, the IC underestimates how close the cell is to its low-voltage cutoff. Under modem transmit load or screen-on draw, voltage dips sharply, and the BMS trips before the reported percentage reaches zero. One full discharge-to-shutoff cycle followed by an uninterrupted charge recalibrates the curve. After that cycle, shutoffs below 15% should stop.

Phone not powering on after the battery sat in storage

Li-ion cells that self-discharge below roughly 2.5V in storage trigger a BMS lockout to prevent cell damage. The 5218S will show no response — no boot logo, no charging animation — when this happens. Plug into a wall charger rather than a USB port; wall chargers deliver enough trickle current to push the cell above the BMS re-enable threshold. Leave it connected for 20–30 minutes before attempting to power on; if the charging LED activates, the BMS has cleared and normal charging will proceed.