I just purchased a new 18v drill. The batteries in my old craftsman drill had crapped out. I was wondering what the best method is for caring for the batteries to ensure that they last a long time. Hopefully, I will not have to take advantage of the warranty anytime soon. Should I run the battery down all the way before charging or just charge it when I am finished working with it for the day? Should I leave the batteries on the charger all the time or just charge them and store them in the case. Is it okay to leave a battery in the drill if I do not use it for several days?