My Ryobi doesn't have this issue at all. The chargers have auto shut-off when the battery is fully charged, so no fire hazard, and none of my 8 batteries has ever discharged over time of non-use. I started adopting the Ryobi 18v system 6 years ago. I have drills, saws, vacuum, trimmer, blower, clipper, radio, light that all use the batteries interchangeably.