About this replacement
Huawei Nova Series — 3.82V Li-Polymer Replacement Battery (HB405979ECW)
This 3.82V, 2900mAh Li-Polymer battery replaces the HB405979ECW cell in the Huawei Nova and Nova Dual SIM, including CAN-L11 and CAN-L13 variants. It fits the original battery bay and connects to the same charge IC and fuel gauge circuit as the factory cell. Swap it when the original cell degrades, swells, or can no longer hold a usable charge across a full day.
- Nova CAN-L11 / CAN-L13 platform fit: These models share the same 3.82V nominal rail, the same HB405979ECW connector footprint, and the same BMS handshake with Huawei's charge IC. One cell covers the full Nova variant list because the hardware platform does not change between single-SIM and Dual SIM configurations.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a CAN-L11 unit, confirmed BMS initialisation, verified the protection circuit tripped correctly at the low-voltage cutoff threshold, and checked that the charge IC accepted the cell without fault flags on the first cycle.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's actual discharge curve before high-current charging is applied to an uncalibrated cell.
Why the Nova reports wrong battery percentage after a cell swap
The fuel gauge IC on the Nova stores a learned discharge curve from the old cell. When a new cell goes in, that stored curve no longer matches the actual voltage profile of the replacement. The IC reads voltage, applies the old map, and outputs a percentage that doesn't reflect real charge state. One complete discharge-to-charge cycle forces the coulomb counter to reset its baseline against the new cell, after which percentage readings stabilise.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem radio or screen backlight draws a current spike that pulls cell voltage below the BMS cutoff threshold — even though the reported percentage looks safe. A fresh cell with an uncalibrated fuel gauge is especially prone to this because the IC doesn't yet know where the actual voltage cliff sits on the new discharge curve. Run the phone through a full calibration cycle first, then check if shutdowns continue. If they do after calibration, verify the cell resting voltage sits above 3.7V with a multimeter before reinstalling.