Let your phone lithium-ion battery charge while you're sitting still—but don't overdo it. Tamarcus Brown/Unsplash Breakthroughs, discoveries, and DIY tips sent every weekday.

Of course, it is completely fine to leave a Ryobi battery on its charger while it's being charged. Otherwise, how could it ever be reused once it's drained? However, you do still want to take it ...