Caterpillar S62 Replacement Battery XQ6602G 3.8V 4000mAh

CATERPILLAR S62 — 3.8V Li-Polymer Replacement Battery (XQ6602G)

This is a 3.8V, 4000mAh Li-Polymer cell (15.2Wh) built to replace the OEM XQ6602G battery in the Caterpillar S62 smartphone. It fits the S62 directly, matching the original connector, cell dimensions (70.20 × 60.30 × 6.00mm), and BMS communication protocol. Capacity figure comes from product data, not a third-party estimate.

• S62 platform fit: The S62 uses a sealed, rugged chassis with a specific connector orientation and BMS handshake tied to the XQ6602G part number. This cell matches that handshake, so the OS recognises the battery and reports status normally without triggering an unverified-battery warning.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the S62 platform. The BMS accepted the cell on first connection, charge current ramped correctly through CC/CV stages, and the fuel gauge IC registered the cell without a fault flag.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.

Sudden shutdown at 20–30% on the S62 after a cell swap

The S62's fuel gauge IC retains the discharge curve of the old, degraded cell. When a new cell arrives, the IC's stored curve no longer matches actual cell voltage under load. The modem and display draw brief high-current spikes that pull cell voltage below the IC's cutoff threshold — even when the displayed percentage looks safe. The fix is one full discharge to auto-shutoff followed by a complete charge cycle, which forces the coulomb counter to reset against the new cell's actual capacity.

USB fast charge not activating on the first cycle after replacement

On first connection with a new cell, the S62's charge IC runs an initialisation check before it enables high-current charging modes. If the BMS has not yet completed its first handshake cycle, the charge IC defaults to trickle or standard 5V input and will not negotiate the fast-charge protocol. This is not a fault with the cell or the charger. Charge fully at standard rate once, then disconnect and reconnect — fast charge will engage normally on subsequent cycles once the BMS handshake is confirmed.