Casper Via V6X Replacement Battery 3.8V 3000mAh

Casper Via V6X — 3.8V Li-Polymer Replacement Battery

This is a 3.8V, 3000mAh (11.4Wh) Li-Polymer cell for the Casper Via V6X smartphone. It fits the Via V6X directly and restores power when the original cell has degraded or no longer holds a usable charge. Dimensions are 86.20 × 66.00 × 4.85mm — confirm these against the original before installation.

• Via V6X platform fit: The Via V6X uses a standard Li-Polymer pouch format at 3.8V nominal. This cell matches the voltage rail, physical footprint, and connector orientation the mainboard expects. No adapter or modification required.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Via V6X platform. The BMS accepted the cell without tripping protection cutoffs, and the fuel gauge IC began tracking state-of-charge within the first full cycle.
• First-cycle fast charge precaution: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's actual discharge curve before high-current charging pushes into an uncalibrated state.

Why the Via V6X reports wrong battery percentage after a cell swap

The Via V6X uses a fuel gauge IC that builds its state-of-charge model around the discharge curve of the original cell. When you swap in a new cell, the IC still references the old curve. Percentage readings can appear stuck, jump erratically, or read 100% while the phone is actually at 70–80%. One full discharge-charge cycle — draining to automatic shutdown, then charging uninterrupted to 100% — forces the IC to remap against the new cell's actual capacity curve. After that cycle, percentage accuracy returns to normal.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — called a voltage cliff — faster than the fuel gauge IC predicted. The modem radio, screen, or both draw a current spike the weakened curve estimate didn't account for, and the BMS cuts power to protect the cell before the OS can warn you. It is most common in the first few cycles when the fuel gauge is still uncalibrated. Run one full discharge-charge cycle and the IC will shift its cutoff threshold to match the real cell voltage behaviour, which pushes the shutdown point below 10%.