Nokia BP-6M 3250 Replacement Battery 3.7V 700mAh

Nokia 3250 / 6280 / 9300i Series — 3.7V Li-ion Replacement Battery (BP-6M)

This is a 3.7V, 700mAh Li-ion replacement for the Nokia BP-6M battery. It fits the Nokia 3250, 6280, 9300i, 3250 XpressMusic, and over ten additional Nokia models from the mid-2000s era. If your original BP-6M has degraded and the phone no longer holds a usable charge, this cell replaces it directly using the same connector and form factor.

• Nokia 3250 / 6280 / 9300i platform: These models share the BP-6M footprint, connector pinout, and voltage rail. One cell fits all of them because Nokia standardised the battery interface across this mid-range lineup — same 3.7V nominal, same physical envelope, same BSI resistor pin for battery identification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on Nokia hardware and confirmed the BMS handshake via the BSI pin. The protection circuit tripped correctly at low-voltage cutoff and charge termination occurred at the expected 4.2V ceiling.
• Fuel gauge recalibration on first cycle: After fitting this cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before use. The Nokia fuel gauge IC was calibrated to your worn original cell — it needs one complete cycle against the new cell's discharge curve to report accurate percentages.

Why the Nokia 3250 shuts down suddenly at 20–30% battery remaining

The Nokia 3250's display and GSM radio together draw a sharp current spike during active use. An aged or fresh-out-of-storage cell with high internal impedance cannot sustain voltage under that load — it drops below the BMS cutoff threshold even though the fuel gauge still shows charge remaining. This is a voltage cliff, not a capacity issue. Fitting a new cell with lower internal resistance eliminates the sag, and one full calibration cycle corrects the percentage readout to match actual remaining charge.

Phone shows incorrect battery percentage after fitting the replacement cell

The Nokia fuel gauge IC stores a discharge curve built from hundreds of cycles on the original cell. A new cell has a different impedance profile, so the IC maps voltage readings to the wrong percentage points — commonly jumping from 60% to 15% with no warning. This is not a fault with the replacement cell. Discharge the phone fully until it powers off automatically, then charge to 100% in one uninterrupted session. After that single cycle the IC recalibrates its curve to the new cell and percentage reporting stabilises.