About this replacement
BLU Studio C Super Camera / D870U — 3.8V Li-Polymer Replacement Battery (TLP15F27)
This is a 3.8V, 2500mAh (9.5Wh) Li-Polymer cell that replaces the original TLP15F27 battery in the BLU Studio C Super Camera and D870U. It fits the same footprint at 75.85 × 59.30 × 4.00mm and connects directly to the stock charge management circuitry. If your original cell is swelling, draining faster than it used to, or failing to charge past a low percentage, this cell replaces it directly.
- Studio C Super Camera and D870U compatibility: Both models share the same PCB layout, connector pinout, and charge IC. The TLP15F27 part number covers both — the BMS handshake, protection circuit, and connector are identical across the two variants.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench and confirmed the protection circuit trips correctly on over-voltage and under-voltage thresholds. The BMS communicates cleanly with the phone's charge IC without triggering an authentication error.
- Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC on the D870U calibrates its coulomb counter against the cell's discharge curve — skipping this step causes the percentage readout to drift or jump erratically during normal use.
Sudden shutdown at 20–30% on the BLU D870U after a cell swap
This happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. When the new cell hits a voltage point the old map didn't predict, the system reads it as a critical low and cuts power — even though charge remains. The fix is one full uninterrupted discharge from 100% down to automatic shutdown, followed by a full charge without interruption. After that single cycle, the coulomb counter resets its learned curve to match the new cell and the shutdowns stop.
Phone showing 100% charge immediately after plugging in the replacement cell
This is a stale fuel gauge state — the IC retained the last known charge level from the removed battery and applied it to the new cell before any measurement cycle ran. It is not a sign the cell is faulty. Power the phone off, leave it on charge for 90 minutes, then power it back on. If the percentage is still misreported, discharge the phone fully until it shuts itself down, then charge to 100% without interruption to force the gauge to relearn from a known floor.