About this replacement
POSH Equal / S700A — 3.7V Li-Polymer Replacement Battery (P7055)
This 3.7V, 2600mAh Li-Polymer cell replaces the original battery in the POSH Equal and S700A smartphones. It matches the OEM part numbers P7055 and GY-288792PL. Capacity figures come from the product specification — 9.62Wh total energy.
- Equal and S700A platform fit: Both the Equal and S700A share the same 3.7V single-cell Li-Polymer architecture, identical connector pinout, and the same BMS handshake protocol — one cell fits both without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the S700A platform. The BMS accepted the charge current without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold under a simulated screen-plus-modem load.
- Fuel gauge recalibration on first use: After installing this cell, disable fast charging and run one full discharge-to-charge cycle before normal use. The fuel gauge IC on the Equal was calibrated to the old cell's discharge curve — one complete cycle lets it map the new cell and prevents erratic percentage readings from the first day.
Sudden shutdown at 20–30% on the POSH Equal after a cell swap
This is a voltage cliff issue, not a capacity issue. Under combined modem and display load, the new cell's terminal voltage drops faster than the fuel gauge IC expects — the phone's under-voltage protection triggers a hard shutdown before the percentage reaches zero. The fuel gauge is still running the discharge model it built for the degraded original cell. One full discharge cycle, letting the phone reach the 3.0V cutoff naturally, resets the coulomb counter and eliminates most cliff shutdowns.
Phone won't power on after the replacement cell sat in storage
Li-Polymer cells lose charge during storage. If the cell voltage dropped below approximately 2.5V, the BMS enters a lockout state to prevent damage — the phone shows nothing when you press the power button. Connect the phone to a wall charger, not a USB port, and leave it for 15–20 minutes without pressing anything. The charge IC on the Equal delivers a trickle current to bring the cell above the BMS re-enable threshold, typically around 2.9V, at which point the phone will boot normally.