You hear so many conflicting things with batteries, I was under the impression that a li ion battery had 800 to 1000 charge cycles and such you were better charging only when you need to, I have a Bosch blue combi drill with two 2ah batteries, for this last maybe six years whenever the power fails, I charge the old battery and swap onto the new, I never charge a half way battery. I use the drill several times a week for home use and the same two batteries are still going strong. Very occasionally I run out of power whilst the spare is charging, normally this is if I'm cutting a series of holes with a cookie cutter style holesaw, but small batteries charge quickly so this isn't a problem for long. I have a few cheap tools, for occasional use, but my combidrill is the absolute heart of my kit and gets used for most jobs, worth every penny, as are the wera screw bits that I use and never need to replace.
