About this replacement
BLU Studio G HD / S170 — 3.7V Li-ion Replacement Battery (C766004220L)
This 3.7V 1600mAh Li-ion cell replaces the original C766004220L battery in the BLU Studio G HD and S170. It fits the removable battery bay directly and restores standard charging and power behaviour. Capacity is 1600mAh — 5.92Wh — matching the factory specification.
- Studio G HD and S170 compatibility: Both models share the same battery bay dimensions, connector pinout, and charge IC handshake. One cell covers both devices — no adapter or modification needed.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Studio G HD platform. The BMS communicated correctly with the charge IC, held cutoff voltage at the expected threshold, and showed no false low-battery trips under screen and modem load.
- Fuel gauge recalibration on first use: After fitting a new cell, disable fast charging if available and run one complete discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the fuel gauge IC a clean discharge curve from the new cell before it begins tracking coulombs accurately.
Why the Studio G HD reports wrong battery percentage after a cell swap
The fuel gauge IC on the Studio G HD learns cell behaviour over time and stores a discharge curve from the old battery. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads voltage, compares it against the old curve, and outputs a percentage that can be 10–20% off. One full discharge-to-shutdown followed by an uninterrupted charge to 100% forces the IC to rewrite its reference curve against the new cell.
Sudden shutdown at 20–30% remaining on the replacement cell
This happens when the cell voltage drops sharply under load — modem transmit bursts and screen backlighting can pull the cell below the BMS protection threshold even though the gauge still shows charge remaining. The BMS trips a hard cutoff to protect the cell, and the phone shuts off. It is not a faulty battery — it is the fuel gauge IC still working from a stale calibration curve. After one full recalibration cycle, the gauge tracks the real voltage cliff correctly and shutdown moves back to the expected 5–10% range.