Both the regular charger and the fast charger can juice up any Ryobi One+ Lithium battery, no matter the amperage. However, 18V One+ batteries are the only batteries that they are rated to work with.

But just how bad is it to leave a fully-charged battery unattended on its charger? Ryobi batteries do have their problems, but accidentally (or even purposely) leaving a lithium battery on its charger ...