Nokia Lumia 900 BP-6EW Replacement Battery 3.7V 1800mAh

Nokia Lumia 900 — 3.7V Li-Polymer Replacement Battery (BP-6EW)

This is a 3.7V, 1800mAh Li-Polymer replacement battery for the Nokia Lumia 900 and Lumia 900 4G LTE smartphones. It uses the OEM part number BP-6EW and slots into the same battery bay as the original cell. Capacity is rated at 6.66Wh.

• Lumia 900 and 900 4G LTE compatibility: Both variants share the same physical battery bay, voltage rail, and connector pinout. The BP-6EW spec covers both — no adapter or modification needed.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Lumia 900 unit. The BMS accepted the charge handshake on the first cycle, and the fuel gauge IC tracked state-of-charge without tripping a protective cutoff.
• Fuel gauge recalibration tip: On first use after fitting this cell, disable any fast-charge modes and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC build an accurate discharge curve for the new cell before higher charge rates are applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the Lumia 900 after a cell swap

This is a voltage cliff issue, not a capacity fault. When the modem transmits or the AMOLED display hits peak brightness, current draw spikes sharply. A new cell that hasn't been through a calibration cycle can drop below the BMS cutoff voltage — around 3.0V — under that load, even when the fuel gauge still reads 20–30%. One full discharge-charge cycle at standard current resolves this. After calibration, the fuel gauge IC maps the actual discharge curve of the new cell and stops triggering premature shutdowns.

Phone won't power on after the replacement battery sat in storage

Li-Polymer cells self-discharge during storage. If the cell voltage has dropped below approximately 2.5V per cell, the BMS enters lockout mode and blocks current flow to protect the cell from damage. The phone will show nothing — no charging animation, no response. Connect to a wall charger, not a USB port, and leave it for 20–30 minutes without pressing the power button. The charge IC needs time to trickle current into the cell until voltage climbs back above the BMS recovery threshold, typically around 2.9V, before normal charging resumes.