About this replacement
BLU Studio G / D790 Series — 3.8V Li-ion Replacement Battery (C71544200T)
This is a 3.8V, 1900mAh Li-ion cell that replaces the original C71544200T battery in the BLU Studio G. It fits the D790, D790U, and D790L variants — all of which share the same battery bay and connector. Capacity figure is 7.22Wh at the rated voltage.
- D790 variant coverage: The D790, D790U, and D790L share an identical battery footprint, connector pitch, and BMS handshake protocol. One cell covers all three — no hardware difference between them at the battery interface.
- Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on D790 hardware. The BMS accepted the cell without error flags, charge termination triggered correctly at 4.2V, and the fuel gauge IC tracked state-of-charge within normal variance across the full curve.
- Fuel gauge recalibration on first use: After installing this cell, disable fast charging for the first complete discharge-charge cycle. The fuel gauge IC on the D790 is calibrated to your old cell's discharge curve. One full cycle at standard current lets it rebuild the coulomb counter baseline against the new cell before high-current charging begins.
Why the BLU Studio G reports wrong battery percentage after a cell swap
The Studio G uses a coulomb-counting fuel gauge IC that builds its state-of-charge model from the old cell's charge and discharge history. When you install a new cell, that learned curve no longer matches the actual cell chemistry. The gauge reads from a stale model, so the percentage shown on screen can drift significantly from real charge state. One full discharge down to automatic shutoff, followed by a complete uninterrupted charge to 100%, forces the IC to re-anchor its endpoints and rebuild the curve against the new cell.
Sudden shutdown at 20–30% on the BLU Studio G
This is a voltage cliff issue, not a capacity issue. Under heavy load — LTE modem activity, screen at full brightness, active apps — the cell voltage drops sharply at low state-of-charge. The phone's protection circuit sees the voltage fall below its cutoff threshold and shuts down before the percentage reaches zero. It typically appears at 20–30% because that is where a new cell's voltage curve drops steeply under load. If it happens consistently at the same percentage, run one full recalibration cycle first. If it persists, check that charge termination is actually reaching 4.2V at the battery terminals.