BLU Dash G C785039200T Replacement Battery 3.7V 1800mAh

BLU Dash G / D490L / D490U — 3.7V Li-ion Replacement Battery (C785039200T)

This is a 3.7V, 1800mAh Li-ion cell that replaces part number C785039200T in the BLU Dash G, D490L, D490U, and Dash X2 smartphones. It restores power to a phone that no longer holds a charge or fails to stay on through normal use. Dimensions are 64.04 × 51.05 × 4.50mm — measure your original cell before installing if you're unsure of the revision.

• Dash G / D490 series compatibility: The D490L, D490U, and Dash X2 share the same physical footprint and connector pinout as the Dash G, which is why a single cell covers this family. The BMS handshake on each device reads cell voltage and temperature over the same two-wire interface, so no firmware differences block the swap.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a BLU Dash G unit. The charge IC accepted the cell without fault flags, and the BMS held cutoff correctly at both ends of the voltage range without tripping prematurely.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. The fuel gauge IC is still calibrated to the old cell's discharge curve — one full cycle lets it remap against the new cell before high-current charging begins.

Why the Dash G reports wrong battery percentage after a cell swap

The Dash G uses a coulomb counter that builds its state-of-charge model from the previous cell's history. When you install a new cell, the IC still references that old curve. Percentage readings can appear frozen, inflated, or drop in large jumps until the IC collects enough discharge data to recalculate. One full discharge from 100% down to automatic shutdown, followed by a full uninterrupted charge, forces the IC to rewrite its reference points. After that cycle, percentage reporting on the Dash G stabilises to within a few percent of actual charge state.

Sudden shutdown at 20–30% on the replacement cell

This shutdown happens when the cell voltage collapses under the combined load of the modem radio and the screen — typically during a call or while streaming. Even though the coulomb counter shows 20–30% remaining, the cell can't sustain voltage above the BMS cutoff threshold under that load spike. It's a cell-voltage issue, not a capacity issue. If it happens consistently, run the recalibration cycle described above first; if shutdowns continue after one full cycle, check that the replacement cell connector is fully seated, since a partial connection raises contact resistance and amplifies the voltage sag.