Ryobi batteries do have their problems, but accidentally (or even purposely) leaving a lithium battery on its charger is generally no more or less dangerous than leaving any electronic device ...

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 .

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 .