Spade Smartphone Replacement Battery 3.7V 1900mAh

Spade Smartphone — 3.7V Li-ion 1900mAh Replacement Battery

This is a 3.7V 1900mAh Li-ion replacement battery for the Spade smartphone. It restores power to a device where the original cell has degraded, swollen, or stopped holding a charge. Capacity is 1900mAh (7.03Wh) — matched to the original specification.

• Spade smartphone fit: This cell matches the voltage rail and physical form factor of the Spade handset. The BMS communicates charge state to the phone's fuel gauge IC over the same signal path as the factory cell.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS held charge cutoff at the correct upper voltage and did not trip on standby or moderate screen-on load.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the Spade reports wrong battery percentage after a cell swap

The fuel gauge IC in the Spade builds a discharge model based on the previous cell's internal resistance and capacity curve. When a new cell goes in, that model is wrong from the first reading. The IC corrects itself by tracking voltage against charge current over one or two full cycles. Until that calibration completes, percentage readings will drift — often reading higher or lower than actual state of charge.

Sudden shutdown at 20–30% on the replacement cell

This happens when the phone's modem or display draws a short burst of current that the cell cannot sustain at low state of charge. Voltage drops below the BMS protection threshold for a fraction of a second and the phone cuts out — even though the fuel gauge still showed charge remaining. It is not a faulty cell. Run one full discharge-charge cycle without fast charging, then check whether the fuel gauge model has corrected. If shutdowns continue past two full cycles, verify the battery connector is fully seated and check for a bent pin on the flex connector.