About this replacement
BLU Neo X Plus / N090U — 3.7V Li-ion Replacement Battery (C936080250P)
This is a 3.7V, 2300mAh Li-ion cell built to replace the original battery in the BLU Neo X Plus (N090U). It matches the OEM part number C936080250P and fits the physical footprint of the Neo X Plus battery bay. Voltage, connector, and BMS communication align to the stock configuration.
- Neo X Plus and N090U compatibility: Both model designations refer to the same hardware platform. The battery connector, BMS handshake protocol, and 3.7V nominal voltage rail are identical across both. One cell covers both.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Neo X Plus platform. The BMS accepted the cell without error flags, and the charge IC cycled correctly through constant-current and constant-voltage phases to full termination.
- 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 recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.
Sudden shutdown at 20–30% on the Neo X Plus after a cell swap
This is a voltage cliff problem. A new cell has a different internal resistance profile than the aged cell the fuel gauge IC was trained on. Under peak load — active LTE modem, screen at full brightness, or a background sync — the new cell's voltage drops faster than the IC expects. The phone interprets this as a critically low charge and cuts power. One full discharge-to-shutdown followed by a complete charge cycle resets the coulomb counter and maps the new cell's voltage curve accurately.
Device not powering on after deep discharge in storage
If the Neo X Plus sat unused for an extended period, the cell voltage may have dropped below 2.5V per cell — the threshold at which the BMS locks out to prevent damage. A standard charger will not wake a cell in this state. Connect the phone to a wall charger and leave it undisturbed for 20–30 minutes without pressing the power button. The charge IC will trickle current into the cell until voltage recovers to the BMS re-enable threshold, typically around 3.0V, at which point normal charging resumes.