About this replacement
Nokia 8 Sirocco — 3.85V Li-Polymer Replacement Battery (HE333)
This is a 3.85V, 3000mAh (11.55Wh) Li-Polymer replacement battery for the Nokia 8 Sirocco smartphone. It fits the standard 8 Sirocco, 8 Sirocco Global TD-LTE, 8 Sirocco Global Dual SIM, and HMD Avatar variants. All share the same battery bay geometry and HE333 connector pinout.
- Nokia 8 Sirocco and HMD Avatar compatibility: These four variants run the same power rail, BMS handshake protocol, and HE333 connector. The fuel gauge IC communicates with the same SMBus lines across all of them, so one cell fits all without pin remapping or firmware differences.
- Bench tested on actual hardware: We cycled this cell through full discharge and recharge on a Nokia 8 Sirocco unit, confirming BMS handshake, charge acceptance, and voltage stability under screen-on and modem-active loads. The cell held 3.85V nominal with no mid-cycle cutoff events.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. 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 Nokia 8 Sirocco after a cell swap
This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a voltage cliff earlier under modem or display load, and the phone's power management IC reads it as a critical low-voltage event before the percentage counter catches up. The OS shuts down to protect the new cell — but the reported percentage is wrong, not the battery. One full discharge from 100% to auto-shutdown, then a full charge without interruption, resets the coulomb counter to the new cell's actual curve.
USB-PD fast charge not working on the first cycle after replacement
On the first cycle, the BMS in a new cell may not immediately complete the USB-PD handshake that authorises high-current charging. The charge IC falls back to standard 5V input instead of negotiating the higher voltage. This is not a fault — it resolves after the first full standard-rate charge cycle completes and the BMS registers the cell as initialised. After that first cycle, reconnect the USB-PD charger and the protocol negotiation should succeed at the expected voltage.