Dr.Tech IP-88 Replacement Battery 3.7V 1000mAh Li-ion

Dr.Tech IP-88 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1000mAh Li-ion cell built to fit the Dr.Tech IP-88 smartphone. It replaces the original battery when capacity has dropped to the point where the phone can no longer hold a usable charge. Dimensions are 46.89 × 44.00 × 5.37mm — confirm your current cell matches before installing.

• IP-88 fit: The IP-88 uses a compact 3.7V single-cell configuration with a fixed connector orientation tied to this footprint. Swapping to a cell outside these dimensions risks contact misalignment or pressure on the rear housing.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles, monitoring BMS cutoff at both ends. The protection circuit tripped correctly at low-voltage threshold and did not allow overcharge beyond rated cell voltage.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before operating under normal load conditions.

Why the IP-88 reports wrong battery percentage after a cell swap

The IP-88's fuel gauge IC stores a learned discharge curve from the original cell. When you install a new cell, that stored curve no longer matches actual cell chemistry and capacity. The OS reads state-of-charge from the coulomb counter's model, not directly from voltage, so the percentage shown can be off by 10–20%. One full discharge below 10% followed by a complete charge to 100% forces the IC to recalibrate against the new cell.

Sudden shutdown at 20–30% remaining on the new cell

This happens when the cell voltage drops sharply under load — called a voltage cliff — before the fuel gauge predicts it should. On the IP-88, screen-on or active call states draw enough current to push a cold or uncalibrated cell below the BMS cutoff threshold faster than the percentage readout expects. The fuel gauge IC hasn't yet mapped where this cell's voltage collapses under that load profile. Run the recalibration cycle first — one full discharge to near 0% and back to 100% — then recheck shutdown behaviour.