About this replacement
Prestigio PAP5450 DUO — 3.7V Li-ion Replacement Battery (PAP5450 DUO)
This is a 3.7V, 1300mAh Li-ion replacement battery for the Prestigio PAP5450 DUO and PSP5457 DUO dual-SIM Android smartphones. It fits directly in place of the original cell when the factory battery no longer holds a charge or fails to power the device. Capacity is rated at 4.81Wh, matching the original specification.
- PAP5450 DUO and PSP5457 DUO fit: Both devices share the same 3.7V cell footprint, connector pinout, and BMS handshake protocol — one battery covers both models without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the PAP5450 DUO platform, confirmed BMS communication was accepted without fault flags, and verified the protection circuit trips correctly at the low-voltage cutoff threshold.
- First cycle after installation: Disable fast charging for the first complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.
Sudden shutdown at 20–30% on the replacement cell
After a cell swap, the fuel gauge IC still holds the discharge curve of the old battery. The new cell has a steeper voltage drop under load — particularly during dual-SIM radio polling or screen-on bursts — and the phone hits the hardware low-voltage cutoff before the OS gauge reaches zero. The result is an abrupt shutdown while the display still shows 20–30% remaining. One full discharge-to-shutdown followed by an uninterrupted charge to 100% forces the coulomb counter to recalibrate against the actual cell curve. After that cycle, reported percentage and true cell state should align.
Device not powering on after sitting in storage
If a PAP5450 DUO has been stored with a depleted battery, the cell can drop below 2.5V per cell — the threshold where the BMS locks out to prevent damage. Plugging in the charger will often show no response, not even a charging indicator. Connect the device to a low-current USB source (500mA wall adapter or PC port, not a fast charger) and leave it connected for 20–30 minutes without attempting to power on. The BMS trickle-charges the cell back above the lockout threshold, typically around 3.0V, at which point normal charging resumes and the device powers on.