About this replacement
Coolpad 9960 — 3.7V Li-Polymer Replacement Battery (CPLD-09)
This 3.7V, 2000mAh Li-Polymer cell is a direct replacement for the Coolpad 9960 smartphone. It fits the original battery bay and connects to the same flex connector and BMS interface as the factory cell. Capacity is rated at 7.4Wh, matching the OEM CPLD-09 specification.
- Coolpad 9960 fitment: The 9960 uses a single-cell Li-Polymer pack at 3.7V nominal, with a three-pin connector carrying charge, ground, and the thermistor signal. This cell replicates that pinout and physical footprint — 58.40 × 54.58 × 4.59mm — so it seats correctly without forcing the rear cover.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the 9960 platform. The BMS accepted the cell without triggering a fault state, and the charge IC brought the pack to 4.2V cutoff within normal parameters on a standard cycle.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated pack.
Sudden shutdown at 20–30% on the Coolpad 9960 after a cell swap
A new Li-Polymer cell has a slightly different voltage-versus-capacity curve than the aged cell the fuel gauge IC was calibrated to. When the modem or display pulls a high-current burst, the cell voltage sags below the BMS cutoff threshold — even though the reported state of charge still reads 25%. The phone interprets this as a critical shutdown event, not a calibration issue. One full discharge-charge cycle without fast charging resets the coulomb counter and aligns the fuel gauge to the new cell's actual curve.
OS percentage jumping erratically after replacement
The Coolpad 9960 stores learned charge data from the previous cell in the fuel gauge IC. After swapping to a new CPLD-09 cell, the IC continues referencing that stale data, which produces jumps — 60% to 45% in seconds, or a sudden leap from 10% to 30% on plug-in. This is a software-side calibration mismatch, not a faulty cell. Let the phone discharge to automatic shutdown, then charge uninterrupted to 100%. Check that the percentage reads stable at 4.2V full charge before resuming normal use.