Nokia G42 5G HQ610 Replacement Battery 3.87V 5000mAh

Nokia G42 5G — 3.87V Li-Polymer Replacement Battery (HQ610)

The HQ610 is a 3.87V, 5000mAh lithium-polymer cell that replaces the original battery in the Nokia G42 5G. It restores full power to the processor, display, and cellular modem when the factory cell has degraded past usable capacity. Capacity matches the original specification at 19.35Wh.

• G42 5G platform fit: The G42 5G uses a single-cell Li-Polymer pack with a specific BMS handshake tied to the phone's charge IC. The HQ610 carries the correct connector pinout and cell impedance profile to pass that handshake without triggering a fault state.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the G42 5G platform. The BMS accepted the cell without fault codes, and the charge IC stepped through trickle, CC, and CV phases as expected on a fresh cell.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the coulomb counter locks in its reference baseline.

Sudden shutdown at 20–30% on the G42 5G after a cell swap

A fresh cell has tighter internal impedance than a worn one. When the G42 5G's modem fires up for a call or data burst, current draw spikes sharply. If the fuel gauge IC is still calibrated to the old cell's curve, it reads the voltage drop as a cliff and shuts the phone down — even though the cell has charge left. This is not a faulty battery. It is a calibration mismatch between the coulomb counter and the new cell. Run one complete discharge to around 3.0V under normal use, then charge fully to 4.35V without interruption. After that cycle the shutdowns stop.

USB-PD fast charge not accepted on the first cycle after replacement

After a cell swap, the G42 5G's charge IC sometimes defaults to standard 5V charging on the first cycle. This happens because the BMS on a new cell starts in a conservative mode until it has completed one full charge handshake with the phone's power management IC. Plug into a USB-PD charger, let the phone charge fully without disconnecting, and then discharge normally. On the second charge cycle the fast charge negotiation resumes at the correct voltage and current profile.