POSH Orion Pro 3.7V 1650mAh Compatible Battery 1ICP38/55/67

POSH Orion Pro / X500a — 3.7V Li-ion Replacement Battery (1ICP38/55/67)

This is a 3.7V, 1650mAh Li-ion cell for the POSH Orion Pro and X500a smartphones. It replaces the original battery when the device no longer holds a charge after repeated charge cycles. Rated at 6.11Wh and measuring 70.50 × 60.00 × 4.00mm, it matches the factory cell dimensions and connector layout.

• Orion Pro and X500a compatibility: Both models share the same battery bay dimensions, connector pin-out, and BMS handshake protocol — the 1ICP38/55/67 part number covers both variants without modification.
• Bench tested on actual hardware: We cycled this cell through a full charge and discharge on the Orion Pro platform. The BMS accepted the charge cycle without triggering overcurrent cutoff, and voltage held steady through screen-on and modem-active load states.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first complete discharge-charge cycle. The Orion Pro's fuel gauge IC is calibrated to the old cell's discharge curve. Running one slow cycle lets it remap against the new cell before high-current charging begins.

Why the Orion Pro reports wrong battery percentage after a cell swap

The Orion Pro uses a fuel gauge IC that tracks charge state by measuring accumulated current flow — a coulomb counter method. When you swap the physical cell, the IC still references its stored discharge curve from the old battery. The new cell has a slightly different internal resistance and capacity curve, so the reported percentage drifts from the actual state of charge. One full discharge to auto-shutdown followed by a full slow charge resets the counter and retrains the curve against the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the modem's minimum operating threshold under combined screen and radio load — even though the fuel gauge still reads 20–30%. A fresh Li-ion cell has slightly higher internal impedance before the first few cycles break it in, which causes a sharper voltage sag under peak draw. The phone's protection circuit reads the sag as a cutoff condition and shuts down before the displayed percentage reaches zero. After two or three full charge-discharge cycles, cell impedance drops and voltage sag stabilises — confirmed stable hold at or above 3.5V under load on our bench after cycle three.