To begin with, always turn off the engine and disconnect the negative terminal before servicing. Also, check the battery for damage, loose connections, or corroded terminals. If corrosion is present, remove the battery for cleaning with a battery brush or terminal cleaner as well as a baking soda solution. Ensure the battery tray and hold-down clamp are in good condition. Remove corrosion with a baking soda solution, and cover damaged parts with a zinc-based primer. The average charging time is 12 to 16 hours with a trickle charger.