About this replacement
BLU Life Play 2 / L170i — 3.7V Li-ion Replacement Battery (C705804180L)
This is a 3.7V, 1200mAh Li-ion cell for the BLU Life Play 2 (L170i) smartphone. It replaces part number C705804180L when the original cell no longer holds charge or the phone shuts down unexpectedly. Physical dimensions are 77.95 × 50.03 × 4.10mm — confirm these match your tray before installing.
- Life Play 2 and L170i compatibility: Both model numbers reference the same hardware revision. They share the same battery tray geometry, connector pinout, and BMS handshake protocol — one cell covers both.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Life Play 2 board. The BMS accepted the cell without error flags, and the charge IC reached cutoff voltage without interruption.
- Fuel gauge recalibration on first use: After installation, run one complete discharge to shutdown and a full charge before re-enabling any fast-charge setting. This gives the fuel gauge IC one clean reference cycle against the new cell's discharge curve — skipping it causes erratic percentage readings early on.
Why the Life Play 2 reports wrong battery percentage after a cell swap
The Life Play 2 uses a coulomb-counting fuel gauge IC that builds its model around the original cell's discharge curve. When you install a new cell, that stored model no longer matches actual cell behaviour, so the percentage display lags or jumps. The fix is one full discharge-to-shutdown followed by an uninterrupted charge to 100%. After that cycle, the IC resets its reference and percentage tracking stabilises.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops below the modem or display's minimum rail voltage under load — even though the reported percentage looks safe. The fuel gauge IC is still running on its old calibration curve, so it shows 20–30% while actual cell voltage has already sagged past the cutoff threshold. Run the phone down to a forced shutdown once, then charge fully without interruption. After that single calibration cycle, the voltage cliff shifts back into the low single digits where it belongs.