About this replacement
Emporia Touch Smart Series — 3.7V Li-ion Replacement Battery (AK-V188)
This 3.7V, 1100mAh Li-ion cell replaces the OEM battery in the Emporia Touch Smart, Touchsmart V188, Touch Smart 2, and TOUCHsmart.2. It fits the same footprint at 53.80 × 42.80 × 5.40mm and connects directly to the existing charge circuit. Capacity matches the original 4.07Wh spec — no modification needed.
- Touch Smart series compatibility: All four listed models share the same chassis, connector pinout, and charge IC handshake. The BMS on each variant expects the same voltage floor and charge-termination signal, so one cell covers the full lineup without any firmware or connector adaptation.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Touch Smart platform. The BMS accepted the cell immediately, held charge termination at 4.2V, and low-voltage cutoff triggered correctly before hitting cell damage threshold.
- Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge to automatic shutoff, then charge uninterrupted to 100% before resuming normal use. The Touch Smart's fuel gauge IC calibrates its coulomb counter to the new cell's discharge curve during this first full cycle — skipping it causes the percentage readout to drift.
Why the Touch Smart 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, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge keeps estimating capacity against old data, so the percentage shown on screen drifts — often reading 40% when the cell is nearly flat. One full discharge-charge cycle forces the coulomb counter to reset and relearn against the new cell's actual curve, bringing the readout back into alignment.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under the load of the modem radio or screen backlight — a voltage cliff the fuel gauge did not predict. The phone's protection circuit cuts power before the displayed percentage reaches zero because actual cell voltage has already fallen below the 3.0V cutoff threshold. It is not a faulty cell — it is an uncalibrated gauge estimating too high. Run one full discharge cycle to shutoff, then charge to 100%, and the gauge recalibrates the cliff point accurately.