Highscreen Spade Li-ion Replacement Battery 3.7V 1900mAh

Highscreen Spade — 3.7V Li-ion Replacement Battery

This 3.7V, 1900mAh Li-ion cell is a direct replacement for the Highscreen Spade smartphone. It fits the original battery slot and connects to the device's charge and fuel gauge circuitry. Use it when your existing cell no longer holds a usable charge or has swollen and needs to come out.

• Highscreen Spade compatibility: The Spade runs a single-cell Li-ion architecture at 3.7V nominal. This replacement matches that voltage rail and the connector pinout the device's PMIC expects. Swapping a mismatched voltage cell here causes charge IC faults.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a test rig, monitoring BMS cutoff behaviour at both the low-voltage floor and the 4.2V top-of-charge limit. The protection circuit tripped cleanly at both thresholds with no overcurrent events during the test discharge.
• Fuel gauge recalibration after install: On first use after installation, disable fast charging for one complete discharge-charge cycle. This allows the fuel gauge IC to recalibrate its internal model against the new cell's actual discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the Spade reports wrong battery percentage after a cell swap

The Spade's fuel gauge IC builds its state-of-charge estimate from a learned discharge curve stored against the old cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The phone reads a residual percentage from the old model, not the real state of the new cell. One full discharge down to automatic shutdown, followed by a complete charge to 100%, forces the IC to relearn the curve and restore accurate percentage reporting.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the PMIC's safe operating floor under a high-load event — typically the modem transmitting at full power or the screen at peak brightness. The fuel gauge still shows 20–30% because it hasn't tracked the voltage cliff yet. The BMS cuts output to protect the cell, and the phone shuts off instantly with no low-battery warning. Run one full calibration cycle first; if shutdowns continue, check that the battery connector is fully seated — a loose pin raises contact resistance and amplifies voltage sag under load.