About this replacement
Highscreen Power Four — 3.8V Li-ion Replacement Battery (Power Four)
This 3.8V, 3000mAh Li-ion cell replaces the original battery in the Highscreen Power Four smartphone. It fits the Power Four directly and matches the original voltage and capacity spec. Install it when the original cell no longer holds enough charge for a full day of use.
- Highscreen Power Four fit: The Power Four uses a fixed connector and BMS handshake tied to the 3.8V nominal rail. This cell matches that rail and the connector pinout, so the phone's charge IC and fuel gauge IC communicate with the replacement the same way they did with the original.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench, confirmed BMS communication stayed active across the full voltage window, and checked that the charge IC accepted current without tripping an overcurrent fault.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC pushes high current into an uncalibrated cell.
Sudden shutdown at 20–30% on the Highscreen Power Four
This is a voltage cliff issue. Under heavy load — modem activity, screen-on, or GPS — the cell voltage drops sharply below what the fuel gauge IC expects at that state of charge. The phone's protection circuit interprets this as a critical low-voltage event and cuts power before the percentage reaches zero. It is most common in the first few cycles on a new cell before the fuel gauge IC has recalibrated. Run two full discharge-charge cycles without fast charging to let the coulomb counter re-anchor to the new cell's actual voltage curve.
Highscreen Power Four not powering on after sitting in storage
If the phone sat for weeks or months with the battery installed and deeply discharged, the BMS may have locked out below 2.5V per cell to prevent damage. In this state the phone will not respond to a standard power button press. Connect it to a wall charger — not a PC USB port — and leave it for 15–20 minutes before attempting to power on. The charge IC needs to trickle current into the cell to bring voltage above the BMS re-enable threshold, typically around 2.8–3.0V, before normal charging resumes.