Nokia 8.1 HE363 Replacement Battery 3.85V 3300mAh

Nokia 8.1 / TA-1119 / TA-1128 — 3.85V Li-Polymer Replacement Battery (HE363)

This is a 3.85V, 3300mAh Li-Polymer replacement battery for the Nokia 8.1 smartphone. It fits model variants TA-1119 and TA-1128 and matches OEM part numbers HE363, HE362, and HE377. Replace the original cell when the phone no longer holds charge through a full day or shuts down unexpectedly under load.

• Nokia 8.1 variant fit — TA-1119 and TA-1128: These two SKUs share the same battery bay geometry, connector pinout, and BMS communication protocol. One cell covers both. Voltage rail and NTC thermistor position are identical across the run.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Nokia 8.1 platform. The BMS accepted the cell without fault codes, and charge IC handshake completed normally on first connection.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated coulomb counter.

USB-PD fast charge not working on first cycle after replacement

After a cell swap, the Nokia 8.1's charge IC defaults to a conservative current limit until it completes one handshake cycle with the new BMS. USB-PD negotiation requires the battery management IC to confirm cell state before the charger steps up to higher voltage. On the first charge, plug into a standard 5V charger — not a fast charger — and let it complete a full cycle. After that cycle, fast charging resumes at full rated current.

Sudden shutdown at 20–30% after the cell swap

This happens when the fuel gauge IC is still reading from the old cell's discharge curve stored in memory. The phone calculates remaining charge against a different voltage-to-capacity map, so it hits the low-voltage cutoff before the displayed percentage reaches zero. The fix is one full discharge below 5% followed by a complete charge to 100% with fast charging off. After that cycle, the coulomb counter re-anchors to the new cell and the shutdowns stop.