ArcMoile Velocity 3.7V 2000mAh Replacement Battery Li-ion

ArcMoile Velocity — 3.7V Li-ion 2000mAh Replacement Battery

This 3.7V, 2000mAh Li-ion cell replaces the original battery in the ArcMoile Velocity smartphone. It fits the Velocity directly and restores power for calls, messaging, and apps. Capacity is 2000mAh (7.4Wh) — identical to the factory spec.

• ArcMoile Velocity fit: The Velocity uses a fixed-form pouch or prismatic cell at 3.7V nominal. This replacement matches the connector pinout and cell dimensions (78.30 × 56.08 × 4.20 mm), so the charge IC and BMS on the mainboard communicate with it the same way they did with the original cell.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench and confirmed the BMS handshake completes correctly — no charge-refused errors and no unexpected thermal cutoff during the initial cycle.
• First-cycle fast-charge tip: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current charging pushes current into an uncalibrated cell reference.

Why the Velocity reports wrong battery percentage after a cell swap

The Velocity's fuel gauge IC stores a learned discharge curve from the original cell. When you install a new cell, that stored curve no longer matches the actual cell chemistry and internal resistance. The OS reads voltage and maps it against the old curve, so it reports percentages that don't match real charge state. One full uninterrupted discharge down to auto-shutoff, followed by a full charge, resets the coulomb counter and re-anchors the gauge to the new cell.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage-cliff failure, not a capacity problem. Under peak modem or screen load, the cell's voltage drops sharply below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. It happens when the fuel gauge IC hasn't yet mapped the new cell's voltage-under-load profile. Run one full slow-charge cycle first, then check that the BMS cutoff floor is sitting at or above 3.0V per cell under normal operating load.