Coolpad 8070 CPLD-91 Compatible Battery 3.7V 1500mAh

Coolpad 8070 / 8028 — 3.7V Li-ion Replacement Battery (CPLD-91)

This is a 3.7V, 1500mAh Li-ion replacement cell for the Coolpad 8070 and 8028 smartphones. It carries OEM part number CPLD-91 and slots into either handset to restore power to the processor, display, and radio stack. Capacity is 1500mAh (5.55Wh) — match this against your original label before installing.

• Coolpad 8070 and 8028 compatibility: Both models share the same 3.7V battery bay, connector pinout, and BMS handshake requirements — one cell covers both devices without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a monitored rig. The BMS held cutoff correctly at both ends of the voltage window, and charge termination triggered cleanly without thermal events.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated register.

Sudden shutdown at 20–30% on the Coolpad 8070 after a cell swap

The 8070's fuel gauge IC holds a discharge curve calibrated to the original cell. A new cell with even slightly different internal resistance will hit a voltage cliff under modem or display load before the gauge reads zero. The phone sees a rail voltage drop it wasn't expecting and shuts down as a protection measure. One full uninterrupted discharge-charge cycle rewrites the coulomb counter and eliminates the premature cutoff.

Phone feels warm near the battery during the first few charges

A new Li-ion cell arrives with higher internal impedance than a conditioned cell. The charge IC on the 8070 pushes current in at the same rate it used with the old cell, and that extra impedance converts some energy to heat. This is normal for the first two to three cycles and reduces as the cell conditions. If the body stays warm past the fifth full charge, check that the back cover is fully seated — trapped heat from a loose cover can amplify the effect.