About this replacement
Sharp Galapagos 003SH — 3.7V Li-ion Replacement Battery (SHI03UAA)
This is a 3.7V, 2500mAh Li-ion cell replacing the original battery in the Sharp Galapagos 003SH smartphone. It also fits the DM009SH and SHI03 variants that share the same battery bay and connector. Capacity is 9.25Wh — matching the stock specification.
- 003SH and DM009SH compatibility: These models share an identical battery connector, BMS handshake protocol, and 3.7V nominal voltage rail — no wiring adapter or firmware change is needed to swap between them.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the 003SH platform. The BMS accepted the cell without error flags, and charge termination triggered correctly at 4.2V.
- First-cycle fast charge: After installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging begins on an uncalibrated state-of-charge map.
Why the 003SH reports wrong battery percentage after a cell swap
The 003SH uses a coulomb counter in the fuel gauge IC that was calibrated to the original cell's discharge curve. A new cell has a slightly different internal resistance and voltage profile — so the IC reads the wrong state of charge until it recalibrates. This shows up as percentages jumping erratically or the phone reporting 15% when it is actually near full. One complete discharge to auto-shutdown followed by an uninterrupted charge to 100% resets the coulomb counter against the new cell. After that cycle, percentage accuracy returns to normal.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff symptom. Under peak modem load or screen brightness, the cell's instantaneous voltage drops faster than the fuel gauge IC anticipates, and the phone cuts out before the displayed percentage reaches zero. It is not a faulty battery — it is the fuel gauge IC firing an under-voltage protection trip on an uncalibrated cell. Run one full discharge-charge cycle without interruption. After recalibration, the IC maps the cliff correctly and shutdown will not occur until the cell voltage approaches 3.0V under load.