A compact unit, lightweight and well designed with a series of LEDs, which show the mode as well as the state of charge from 9V to 13.2V. We like the natty plastic clip for hanging on the window, and there's more versatility with the optional cigar-lighter lead, at an extra ΂£10. The Airflow charged between 0.35A to 0.4A most of the time, but wouldn't pick up batteries much below 9.5V, so a really flat powerpack would need boosting first.