About this replacement
BLU Studio 7.0 HD — 3.8V Li-Polymer Replacement Battery (C1275703300P)
This 3.8V, 3000mAh Li-Polymer battery replaces the original cell in the BLU Studio 7.0 HD and its variants — D700A, D700i, and D700. It matches the OEM part number C1275703300P and fits the same 125.00 × 56.50 × 3.10mm footprint. Capacity is rated at 11.4Wh, consistent with the original specification.
- Studio 7.0 HD series compatibility: The D700A, D700i, and D700 variants share the same battery bay dimensions, connector pinout, and BMS handshake voltage rail. One cell fits the entire line without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on BLU Studio 7.0 HD hardware. The BMS accepted charge without flagging overvoltage, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before normal use. This lets the phone's fuel gauge IC build an accurate discharge curve against the new cell before high-current charging is applied to an uncalibrated pack.
Why the Studio 7.0 HD reports wrong battery percentage after a cell swap
The fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, the IC is still reading against that old curve, so the percentage shown on screen drifts from the actual state of charge. This mismatch is most visible in the 30–60% range, where the original cell had accumulated wear. One full discharge cycle down to automatic shutdown — followed by a complete charge to 100% — resets the coulomb counter and lets the IC re-map against the new cell's actual capacity.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under load from the modem or display — a voltage cliff the fuel gauge did not predict. The phone's reported percentage is still positive, but the actual cell voltage has fallen below the BMS cutoff, typically around 3.0–3.2V under peak draw. A fresh Li-Polymer cell can show this behaviour on the first few cycles before the electrolyte fully wets the electrode stack. Run two or three full charge-discharge cycles at normal use; the voltage sag under load will reduce as the cell conditions, and the shutdowns should stop.