Nokia 8210 BLB-2 Replacement Battery 3.7V 1000mAh

Nokia 8210 / 8310 Series — 3.7V Li-ion Replacement Battery (BLB-2)

This is a 3.7V, 1000mAh Li-ion replacement cell for the Nokia 8210, 8310, 8250, and 8270, along with fifteen additional Nokia handsets that share the BLB-2 footprint. It replaces a depleted or swollen original cell and restores the phone to normal calling and messaging operation. Voltage and physical dimensions match the OEM spec: 52.95 × 33.07 × 8.01mm.

• BLB-2 platform compatibility: The 8210, 8310, 8250, and 8270 all run the same narrow-body PCB layout and share an identical battery bay geometry. Nokia standardised the BLB-2 connector and contact rail across this series, so one cell fits the full lineup without modification.
• Bench tested on actual hardware: We cycled this cell on an 8210 and 8310 unit. The BMS accepted charge from a standard Nokia pop-port charger without refusing the session, held voltage above 3.6V through a full discharge cycle, and triggered low-voltage cutoff cleanly at the correct threshold rather than dropping suddenly.
• Fuel gauge recalibration after install: On first use, run the phone to automatic shutdown, then charge uninterrupted to 100% before using it again. This gives the coulomb counter a full reference sweep against the new cell's actual discharge curve — skipping this step is the main reason percentage readings appear off after a cell swap.

Why the Nokia 8210 reports wrong battery percentage after a cell swap

The 8210 uses a simple fuel gauge IC that builds its capacity model from accumulated charge and discharge data. When you fit a new cell, that model still reflects the old cell's degraded curve. The IC will report percentages based on stale reference points until it collects fresh data. One full discharge to cutoff followed by a complete uninterrupted charge resets the reference and brings the displayed percentage back in line with actual cell state.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens because the phone's modem transmit bursts pull current spikes the cell cannot sustain while the terminal voltage is already declining. Even though the fuel gauge reports 20–30% remaining, the cell voltage collapses below the cutoff threshold under that instantaneous load. It is a voltage-cliff failure, not a capacity failure. The fix is the same recalibration cycle — one full discharge to shutdown, then charge to 100%, which lets the fuel gauge IC learn where the real voltage cliff sits on this specific cell.