Just a hint that any gizmo can be hands free or have two dozen knobs and meters.
But if it cannot charge a battery completely then it is worthless.
70% to 90% incorrectly "full charge" batteries are the bane of true green technology. Battery manufacturers love it. I would estimate 95% of the smart-genius-einstein-enrico fermi charger gizmos out there do not charge a battery completely.
And you pay through the snot-box for sloppy maintenance. If the charge cycle does not revert the electrolyte to 100% density the battery is not charged. It is one of the few black & white inarguable issues out there.