Nokia BL-4U 8800 Arte Replacement Battery 3.7V 1000mAh

Nokia 8800 Arte Series — 3.7V Li-ion Replacement Battery (BL-4U)

This is a 3.7V, 1000mAh Li-ion cell built to the BL-4U specification. It fits the Nokia 8800 Arte, 8800 Sapphire Arte, 8800 Carbon Arte, 8800 Gold Arte, and over 20 additional 8800-series variants. Same voltage, same connector, same BMS handshake as the original Nokia cell.

• 8800 Arte series compatibility: All 8800 Arte variants share the same battery bay dimensions, 3.7V single-cell architecture, and BL-4U connector pinout. The BMS handshake protocol is identical across the lineup, so one cell covers the full range without modification.
• Bench tested on actual hardware: We cycled this cell on an 8800 Arte body. The BMS accepted charge on first connect, current tapered correctly at top-of-charge, and the protection circuit tripped cleanly at the low-voltage cutoff threshold. No false charge-complete flags during testing.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable any fast-charge accessory for the first complete discharge-to-charge cycle. This lets the phone's fuel gauge IC map the new cell's discharge curve before applying high charge current to an uncalibrated cell.

Why the 8800 Arte reports wrong battery percentage after a cell swap

The 8800 Arte uses a fuel gauge IC that builds its state-of-charge model from the previous cell's discharge history. When a new cell goes in, that stored curve no longer matches the actual cell chemistry. The gauge reads voltage and applies the old lookup table, producing percentage figures that don't reflect real capacity. One full discharge down to automatic cutoff, followed by a full charge, resets the calibration and brings percentage reporting back into alignment.

Sudden shutdown at 20–30% on the 8800 Arte after replacement

This happens when the cell voltage drops below the phone's minimum operating threshold under load — typically during a call, screen-on burst, or radio scan — even though the gauge still shows charge remaining. A fresh Li-ion cell with an uncalibrated fuel gauge can show 25% while actual open-circuit voltage is already near 3.5V. Under the current draw of the GSM transmitter, voltage sags further and the BMS cuts out. Run one full calibration cycle first; if shutdowns persist after calibration, check that the battery contacts in the bay are clean and making full contact. Target resting voltage after a full charge should read 4.1–4.2V on a multimeter at the cell terminals.