Note, when you buy a car battery than you need a charger that is a good fit for your car battery size. Otherwise, you're looking at a dangerous and possibly more expensive situation. Note, you can find the size description on the back or on the top. Imagine the massive amounts of money you would save if you could charge it yourself - as opposed to giving the job to a mechanic. Oh, by the way, do any of you charge the batteries in the correct way or have you gotten by doing it the other way? Do you charge your own batteries?