BlackView R6 BL1549I Replacement Battery 3.8V 3000mAh

BlackView R6 — 3.8V Li-Polymer Replacement Battery (BL1549I)

This is a 3.8V, 3000mAh lithium-polymer replacement battery for the BlackView R6 smartphone. It carries OEM part number BL1549I and fits the R6 directly. Swap it in when the original cell can no longer hold charge or causes unexpected shutdowns.

• BlackView R6 fit: The R6 uses a fixed battery bay sized to this cell's 80.10 × 61.36 × 3.76mm footprint. The BMS connector pinout matches the phone's charge IC, so the handshake initialises without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench, confirming the BMS cutoff engages correctly at the low-voltage threshold and that the charge IC accepts the cell without fault flags.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one full discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Why the R6 reports wrong battery percentage after a cell swap

The R6's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads against the old curve and reports inaccurate percentages — often inflated early in a charge and deflated near the bottom. One full discharge to automatic shutdown followed by a complete uninterrupted charge resets the coulomb counter and re-anchors the curve to the new cell.

Sudden shutdown at 20–30% on the BlackView R6

This is a voltage cliff issue, not a capacity issue. Under load from the modem or screen, the cell voltage drops faster than the fuel gauge predicts, hitting the BMS low-voltage cutoff before the display reads zero. It happens most often when the fuel gauge IC is still calibrated to a degraded original cell. Run one full discharge-charge cycle without fast charging — this recalibrates the gauge — and check that the reported percentage at shutdown is closer to 0–5% before concluding there is a hardware fault.