BLU Hero 2 Replacement Battery N4D110J 3.7V 950mAh

BLU Hero 2 — 3.7V Li-ion Replacement Battery (N4D110J)

This is a 3.7V, 950mAh Li-ion battery for the BLU Hero 2 smartphone. It replaces OEM part number N4D110J. Fit this cell when the original no longer holds a useful charge or fails to power the device at all.

• Hero 2 cell compatibility: The Hero 2 uses a fixed voltage rail at 3.7V nominal with a connector and BMS handshake matched to the N4D110J cell format. Swapping to this replacement keeps the charge IC operating within its expected current and temperature thresholds.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Hero 2 platform. The BMS accepted charge on first connection, cell voltage climbed to 4.2V at full charge, and protection circuits tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the Hero 2 after a cell swap

The Hero 2's fuel gauge IC retains the discharge curve of the old, degraded cell after replacement. When the new cell's actual voltage drops quickly under modem or screen load near a certain state-of-charge, the IC misreads it as a safe level — then hits the hardware cutoff without warning. The OS never gets a low-battery signal in time. One full discharge-to-shutdown followed by an uninterrupted charge to 4.2V resets the coulomb counter and corrects percentage reporting.

Hero 2 not powering on after the battery sat discharged in storage

Li-ion cells that self-discharge below approximately 2.5V trigger the BMS lockout circuit as a safety measure — the phone will show nothing on screen, even on charge. Connect the device to a low-output charger (a standard 5V/500mA USB port, not a fast charger) and leave it for 20–30 minutes without pressing the power button. The BMS trickle-charges the cell back above the lockout threshold before allowing normal charge current. Once the battery indicator appears on screen, the cell is recovering.