Coolpad CPLD-24 Replacement Battery 3.7V 1100mAh

Coolpad 2938 / D60 — 3.7V Li-ion Replacement Battery (CPLD-24)

This is a 3.7V, 1100mAh Li-ion cell built to the CPLD-24 specification. It fits the Coolpad 2938 and D60 smartphones. Voltage and connector match the original, so the existing charge IC and BMS handshake cycle correctly on installation.

• Coolpad 2938 and D60 compatibility: Both models share the CPLD-24 form factor — same 60.16 × 44.77 × 5.20 mm footprint, same 3.7V nominal rail, and the same BMS communication lines. One cell covers both devices without adapter or modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS accepted charge current without triggering overvoltage cutoff, and the protection circuit responded correctly at the low-voltage threshold — no false lockouts observed.
• Fuel gauge recalibration after swap: On first use after installation, run one full discharge down to auto-shutdown, then charge uninterrupted to 100% before using the phone heavily. This lets the fuel gauge IC map the new cell's discharge curve — skipping this step causes erratic percentage jumps in the first few days.

Sudden shutdown at 20–30% on the Coolpad 2938

This is a voltage cliff issue, not a capacity problem. Under peak load — modem transmission, screen at full brightness, or app bursts — the cell voltage drops faster than the fuel gauge IC expects and crosses the BMS cutoff threshold while the reported percentage still reads high. It happens most often in the first week after a cell swap, before the coulomb counter has recalibrated. Run two full discharge-to-shutdown cycles followed by uninterrupted charges, and the shutdowns typically stop. If they continue past cycle three, check that the battery connector is fully seated — an intermittent contact amplifies the voltage sag effect.

Phone not powering on after the replacement battery sat in storage

Li-ion cells self-discharge during storage, and if the CPLD-24 drops below approximately 2.5V, the BMS enters lockout mode to prevent cell damage — the phone will not respond to the power button or show a charging screen. Connect the phone to a wall charger (not a PC USB port) and leave it for 15–20 minutes without pressing anything. The charge IC trickle-feeds current into the locked-out cell until voltage recovers above the BMS wake threshold, typically around 3.0V, at which point normal charging resumes and the screen responds.