I had to keep up the battery on a 1999 Mercedes that is driven less than 50 miles a year. Verified purchase: Yes Condition: New Sold by: 805hartan remember this is made in China where quality control is not a thing.
look on the harbor freight website and see all the people in the reviews who have left bad reviews about this. this isn't a battery maintainer, it is a trickle charger which can and will ruin your battery if left hooked up for too long. i checked mine with a multimeter when i received it.
anything higher will boil the acid in your battery and ruin your battery. it is not a problem as long as it is not putting out more than 13.6 volts. these things do NOT have an automatic shutoff when you battery is full. These things do NOT have an automatic shutoff when you battery is full.
