About this replacement
Nokia 5.4 — 3.85V Li-Polymer Replacement Battery (HQ430)
This is a 3.85V, 3900mAh Li-Polymer replacement battery for the Nokia 5.4 and Nokia 3.4 smartphones. It replaces OEM part number HQ430 and restores power to devices where the original cell has degraded or failed. Fit models include the Nokia 5.4, 5.4 2021, and HMD 5.4 variants.
- Nokia 5.4 and 3.4 compatibility: These models share the HQ430 cell form factor — same connector pinout, same BMS handshake protocol, and identical 3.85V nominal voltage rail. Swapping between these variants does not require any wiring or adapter change.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a Nokia 5.4 unit. The BMS accepted the cell without error flags, and the charge IC stepped through its constant-current and constant-voltage phases correctly at both standard and fast-charge rates.
- Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current fast charging begins pushing current into an uncalibrated cell.
Sudden shutdown at 20–30% on the Nokia 5.4 after a cell swap
The Nokia 5.4's fuel gauge IC retains the discharge curve of the old cell after a swap. When the modem fires or the screen peaks at full brightness, current draw spikes and the new cell's actual voltage drops below what the fuel gauge expects at that state of charge. The phone interprets this as a critical voltage event and shuts down even though the cell is not empty. One full discharge-charge cycle without fast charging resets the coulomb counter and resolves the shutdown behaviour.
Device not powering on after the replacement battery sat in storage
Li-Polymer cells self-discharge in storage, and if the cell voltage dropped below approximately 2.5V before installation, the BMS will lock out charging as a protection measure. The phone will show no sign of life when connected to a charger. Connect the device to a wall charger — not a USB port — and leave it for 20–30 minutes without pressing any buttons. If the cell voltage recovers above the BMS wake threshold of around 2.7V, the charge IC will resume and the phone will boot normally.