About this replacement
Coolpad 8707 — 3.7V Li-ion Replacement Battery (CPLD-145)
This is a 3.7V, 1500mAh Li-ion replacement battery for the Coolpad 8707 smartphone. It matches OEM part number CPLD-145 and fits the Coolpad 8707 directly. Install it when the original cell no longer holds charge or has failed completely.
- Coolpad 8707 fit: The 8707 uses a fixed voltage rail at 3.7V nominal with a specific connector pinout tied to the CPLD-145 cell. Swapping to any other cell spec breaks the BMS handshake and prevents the phone from booting.
- Bench tested on actual hardware: We ran this cell through a full charge cycle on the 8707 board. The BMS accepted the charge profile without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
- 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 into an uncalibrated state.
Why the Coolpad 8707 reports the wrong battery percentage after a cell swap
The 8707's fuel gauge IC uses a coulomb counter trained on the original cell's charge and discharge curve. When you install a new cell, the IC still references the old curve, so percentage readings are inaccurate from the start. This is normal and not a fault with the replacement battery. Run one full discharge down to automatic shutdown and one full charge to 100% to let the IC remap its reference table against the new cell.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under load — typically when the modem is transmitting or the screen is at full brightness — even though the fuel gauge still shows charge remaining. The new cell's internal resistance is slightly higher than the aged original, so voltage sags below the BMS cutoff threshold under peak draw. The fuel gauge IC has not yet learned where the real voltage cliff sits on this cell. Complete two full discharge-charge cycles without fast charging; the cutoff behaviour typically stabilises once the IC recalibrates to the new cell's voltage floor, usually around 3.4–3.5V under load.