About this replacement
Sugar Y8 Max — 3.85V Li-Polymer Replacement Battery (1ICP/4/62/74)
This is a 3.85V, 2950mAh Li-Polymer cell that replaces the original battery in the Sugar Y8 Max smartphone. It fits the OEM footprint at 73.80 × 61.62 × 3.85mm and connects to the same charge IC the phone expects. Capacity is 11.36Wh — matching the original specification.
- Y8 Max fit confirmation: The Y8 Max uses a single-cell Li-Polymer pack at 3.85V nominal. This cell matches that voltage rail and the OEM part number 1ICP/4/62/74, so the BMS handshake between the cell and the phone's charge IC proceeds without flags or charge inhibit.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a smartphone battery analyser. The BMS held cutoff at the correct upper and lower voltage thresholds, and charge current tapered normally as the cell approached capacity.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. The fuel gauge IC in the Y8 Max calibrates its coulomb counter against the new cell's discharge curve — running a slow cycle first prevents the gauge from inheriting the old cell's degraded profile.
Why the Y8 Max reports wrong battery percentage after a cell swap
The Y8 Max uses a fuel gauge IC that builds a discharge model from historical cycle data stored against the old cell. When a new cell goes in, that stored model no longer matches the actual cell chemistry. The gauge reads voltage and estimates charge state from a curve that no longer applies, so it can show 40% and then drop to 5% in minutes. One full slow discharge to shutdown followed by a full charge resets the coulomb counter and lets the IC rebuild an accurate curve against the new cell.
Sudden shutdown at 20–30% on the replacement cell
This happens when the fuel gauge IC has not yet recalibrated and the phone hits a voltage cliff under load — typically when the modem fires a transmission burst or the display peaks at full brightness. The cell voltage drops faster than the gauge predicted, and the phone shuts down to protect the cell before the displayed percentage reaches zero. It is not a defective cell. Run one uninterrupted discharge cycle to shutdown without charging mid-way, then charge to 100% without interruption — after that cycle the gauge tracks the new cell accurately and the early shutdowns stop.