Amazing A2 Replacement Battery 3.7V 1400mAh Li-ion

Amazing A2 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1400mAh Li-ion replacement battery for the Amazing A2 smartphone. It slots into the A2 and restores power to the display, processor, and radio stack. Dimensions are 59.40 × 46.00 × 5.10mm — confirm clearance before installing.

• Amazing A2 fit: The A2 runs a single-cell 3.7V nominal architecture. This cell matches that voltage rail and the physical connector orientation the A2 mainboard expects. No voltage mismatch, no connector adapter needed.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS held charge termination correctly at 4.2V and did not trigger premature cutoff under simulated screen and modem load.
• Fuel gauge recalibration after install: On first use, disable fast charging and run one full discharge-charge cycle from 100% down to automatic shutdown, then back to full. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before fast charging applies high current to an uncalibrated cell.

Sudden shutdown at 20–30% on the A2 after a cell swap

This is a voltage cliff issue, not a capacity defect. When the A2's modem and display pull current simultaneously, the new cell's voltage drops faster than the fuel gauge IC expects based on the old cell's curve. The phone's low-voltage protection trips and forces a shutdown before the percentage reads zero. Running one full discharge cycle lets the coulomb counter recalibrate and the shutdowns stop.

A2 not powering on after the replacement cell sat in storage

Li-ion cells self-discharge during storage. If the cell dropped below approximately 2.5V per cell, the BMS locks out to prevent damage and the phone will not respond to a power button press. Connect the A2 to a charger and leave it for 15–20 minutes without pressing anything — the charge IC needs time to trickle current into the cell before voltage climbs high enough for the BMS to unlock and allow normal charging to resume.