CAT S62 XQ6602G Replacement Battery 3.8V 4000mAh

CAT S62 — 3.8V Li-Polymer 4000mAh Replacement Battery (XQ6602G)

This is a 3.8V Li-Polymer cell rated at 4000mAh (15.2Wh), built to fit the CAT S62 rugged smartphone. It replaces OEM part XQ6602G when the original cell no longer holds a usable charge. The S62's thermal camera and always-on sensors draw steady current, so a degraded cell shows fast in field use.

• S62 platform fit: The CAT S62 uses a dedicated connector and BMS handshake tied to the XQ6602G cell spec. This replacement matches the voltage rail, physical footprint (70.20 × 60.30 × 6.00mm), and BMS communication protocol the S62 motherboard expects.
• Bench tested on actual hardware: We cycled this cell through charge and load on the S62 platform. The BMS accepted charge current without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold — no runaway, no false lockout.
• First-cycle fast charge caution: After installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the S62's fuel gauge IC recalibrate against the new cell's discharge curve before high-current fast charging pushes into an uncalibrated state.

Why the CAT S62 reports wrong battery percentage after a cell swap

The S62 uses a coulomb-counting fuel gauge IC that builds its model from the previous cell's charge history. When you swap cells, that model is stale — it still references the old cell's capacity curve. The percentage shown on screen can be off by 10–20%, especially in the middle range. One full discharge to automatic shutdown, followed by an uninterrupted charge to 100%, forces the IC to re-anchor its curve to the new cell.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the fuel gauge IC hasn't recalibrated and the reported percentage no longer matches actual cell voltage. Under load — modem handoff, thermal camera polling, or screen at full brightness — the cell voltage drops faster than the stale model predicts. The BMS sees voltage fall below its cutoff threshold and shuts the phone down even though the OS still shows charge remaining. Run one full cycle at standard charge rate, and check that the phone reaches 4.20V at the charge pin before calling the cycle complete.