About this replacement
Emporia Smart / Smart 1 — 3.8V Li-ion Replacement Battery (AK-S1)
This is a 3.8V, 2600mAh Li-ion replacement battery for the Emporia Smart and Smart 1 smartphones. It uses OEM part numbers AK-S1 and AK-S1(V1.0). If the original cell is swelling, failing to hold charge, or causing unexpected shutdowns, this is the direct swap.
- Smart and Smart 1 fitment: Both models share the same battery bay dimensions and BMS connector pinout. At 64.66 × 56.99 × 5.25 mm, the cell seats flush against the frame contacts without adapter plates or cable modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Smart platform. The BMS accepted the charge IC handshake without fault codes, and the protection circuit tripped correctly at low-voltage cutoff — no thermal events during the test cycle.
- Fuel gauge recalibration after install: On first use, disable fast charging and run one full discharge-to-charge cycle before switching fast charge back on. The fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve on that first cycle — skipping it can cause erratic percentage readings for several days.
Sudden shutdown at 20–30% on the Emporia Smart after a cell swap
A new cell has a slightly different voltage-versus-capacity curve than the original. The phone's fuel gauge IC was calibrated to the old cell, so it reads voltage drop incorrectly and does not see the cliff coming. Under modem or screen load, the cell voltage dips sharply below 3.4V before the OS expects it, triggering an emergency shutdown. One complete discharge-to-charge cycle resets the coulomb counter and maps the new curve, after which the phone should report percentage accurately down to around 3.2V under load.
Phone will not power on after the replacement battery sat in storage
Li-ion cells in storage self-discharge over weeks. If the cell drops below 2.5V per cell, the BMS enters a lockout state to prevent damage — the phone shows nothing on screen and does not respond to the power button. Connect a charger rated at least 5V 1A and leave it for 20–30 minutes without pressing anything. The BMS needs a trickle current to recover enough voltage to unlock before normal charging resumes. If the charge indicator still does not appear after 30 minutes, try a second charger to rule out a cable or adapter fault.