About this replacement
Nokia 8.3 5G / TA-1243 / TA-1251 — 3.85V Li-Polymer Replacement Battery (HQ480)
This is a 3.85V, 4400mAh (16.94Wh) Li-Polymer replacement cell for the Nokia 8.3 5G (2020), also sold as the Nokia 8 V 5G. It fits TA-1243 and TA-1251 variants and replaces the original HQ480 battery. Install it when the original cell no longer holds a charge or causes unexpected shutdowns.
- TA-1243 and TA-1251 compatibility: Both variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol — the HQ480 footprint at 87.74 × 64.00 × 4.70mm covers both without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Nokia 8.3 platform. The BMS accepted the cell, reported state of charge correctly after one full calibration cycle, and held voltage under 5G modem load without triggering protective cutoff.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and complete one full discharge-charge cycle at standard rate. The fuel gauge IC on the Nokia 8.3 calibrates its coulomb counter against the new cell's discharge curve — skipping this step causes erratic percentage readings and early shutdowns until recalibration completes.
Sudden shutdown at 20–30% on the Nokia 8.3 5G after a cell swap
The Nokia 8.3 runs a Snapdragon 765G paired with a 5G modem — both spike current draw sharply under load. If the fuel gauge IC has not yet recalibrated to the new cell's discharge curve, it reports a higher state of charge than the cell can actually sustain under that current spike. The cell voltage drops below the BMS cutoff threshold before the OS reads 0%, causing a hard shutdown at an apparent 20–30%. One full discharge-charge cycle at standard rate resets the coulomb counter and eliminates this behaviour.
USB-PD fast charge not engaging on the first cycle after replacement
After installing a new HQ480 cell, some Nokia 8.3 units default to standard 5W charging on the first cycle rather than accepting USB-PD fast charge negotiation. The charge IC limits input current when it detects an uncalibrated cell with no charge history — this is a protective behaviour, not a fault. Complete one full standard charge cycle first. On subsequent charges, connect a USB-PD charger rated at 18W or above and fast charging resumes at the expected rate.