CyberBank POZ X301 Replacement Battery SP70A 3.7V 2400mAh

CyberBank POZ X301 — 3.7V Li-Polymer Replacement Battery (SP70A)

This is a 3.7V, 2400mAh lithium-polymer cell built to replace the original SP70A battery in the CyberBank POZ X301 smartphone. It restores power to the processor, display, and cellular radio after the factory cell has degraded through repeated charge cycles. Voltage and capacity match the original specification exactly.

• POZ X301 fitment: The X301 uses a sealed Li-Polymer pouch format with a specific connector pitch and BMS handshake tied to the SP70A part number. Swapping in a cell that matches the original voltage curve and connector layout keeps the charge IC operating within its normal charge termination window.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the POZ X301 platform and monitored BMS behaviour at both ends of the voltage range. The protection circuit responded correctly at low-voltage cutoff and did not trip during normal screen-on load.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the POZ X301 after a cell swap

The fuel gauge IC on the X301 stores a discharge curve learned from the original cell. When a new cell goes in, the stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. Under heavy load — active LTE, GPS, or screen at full brightness — the cell voltage can sag below the BMS cutoff threshold while the OS still reports 20–30% remaining. The fix is one full uninterrupted discharge cycle from 100% down to automatic shutoff, then a full charge without interruption. After that cycle the coulomb counter resets against the real cell curve and the shutoffs stop.

USB fast charge not activating on the first cycle after replacement

The charge IC on the POZ X301 runs a handshake with the battery BMS before it allows elevated charge current. On a fresh replacement cell, that handshake can fail on the first plug-in because the BMS has not yet completed an initialisation cycle. The phone charges slowly or falls back to standard 5V charging. Disconnect the cable, power the phone off fully, then reconnect — on the second connection the BMS handshake completes and fast charge resumes at its normal voltage.