I purchased this as the saw that i purchased did not come with the charger. First time i used it i placed the battery into the saw and it immediately started smoking. I detached it thinking a fire may start than waited an hour or so. an hour later it did not work and did not charge the saw. i waited until the next day and it finally worked so i attached the saw blade and went to the garage to use it and the charge only lasted 5 minutes before it died. I recharged it and again the charge only lasted five minutes. i assume the problem is this battery pack but it could be the saw but i doubt it because the saw works it just noticeably loses power after five minutes. i cant use this at all because of that. I need cordless and can't use corded version. What junk!!!