Cat S48c Smartphone Compatible Battery L6880 3.8V 3800mAh

Sprint Caterpillar Cat S48c — 3.8V Li-Polymer Replacement Battery (L6880)

This 3.8V, 3800mAh Li-Polymer battery replaces the OEM L6880 cell in the Caterpillar Cat S48c rugged smartphone. It restores full power capacity to the device after the original cell has degraded or failed. Dimensions are 98.16 × 57.80 × 4.30mm — confirm fit before installation.

• Cat S48c platform fit: The S48c uses a sealed, non-removable-style bay with a BMS that handshakes over a dedicated ID line. The L6880 part number identifies the correct cell chemistry and connector pinout for this bay. A mismatched cell will either be rejected by the charge IC or report incorrect state-of-charge data to the OS.
• Bench tested on actual hardware: We cycled this cell through charge, load, and BMS cutoff on the S48c platform. The fuel gauge IC accepted the new cell and the BMS held the 4.35V charge ceiling without tripping thermal cutoff at room temperature.
• First-cycle fuel gauge reset: After installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's actual discharge curve before high-current fast charging applies load to an uncalibrated cell.

Sudden shutdown at 20–30% on the Cat S48c after a cell swap

The Cat S48c's fuel gauge IC stores a discharge curve calibrated to the old cell. A new cell has a slightly different voltage-to-capacity curve, which can create a mismatch where the OS reads 25% remaining while actual cell voltage has already dropped below the modem's minimum operating voltage. Under a high-draw event — LTE transmission, GPS lock, or screen-on — the phone shuts down to protect the SoC. This is not a fault in the replacement cell. One full discharge cycle from 100% to automatic cutoff, followed by a full charge, recalibrates the coulomb counter and eliminates the cliff.

USB-PD fast charge not activating on the first cycle after replacement

Some charge ICs run a handshake check on the first connection after a new cell is detected — they default to standard 5V/1A until the BMS reports a valid cell state. If the S48c is not showing the fast-charge indicator on the first plug-in, this is expected behaviour. Let the first charge complete at standard rate. On the second charge cycle, the fast-charge protocol should re-engage. If it does not engage by cycle two, confirm the cable supports USB-PD and that the adapter output is at least 9V/2A.