In an age when our devices have become extensions of ourselves, the question of how to keep them alive away from the wall has quietly become a matter of daily consequence. Four portable power banks — ranging from $70 compact units to $300 professional-grade bricks — each answer a different version of that question, from magnetic simplicity to raw multi-device output. Tested against real-world demands, they reveal that the right choice is less about specifications and more about understanding your own habits and needs. Beneath the convenience, though, lies a reminder that energy storage carries