Instruct: Classify the given Amazon review into its appropriate rating category
Query: Overheated and melted when used with Ryobi Brushless Trimmer

These batteries worked GREAT for many applications and tools. However, less than two years after purchasing, heavy use with my Ryobi brushless trimmer caused the batteries to overheat and the area around the contacts melted. Almost ruined my trimmer, as one of the batteries almost wouldn't come out. Neither are currently functional. I have purchased 4 of these, as I gave two to my son-in-law as a gift. I also own some of the actual Ryobi batteries which I have owned for years, and have had no problem. I can't recommend Energup at this point, unless you are only doing light-duty stuff.