Do I need two 6-V units, one for each battery, or can I install one 12-V unit and attach it to both batteries in series (one clamp on one battery negative and other clamp on 2nd battery positive)? Can it be installed permanently on the batteries and a plug run outside the trunk or to the interior where I can plug it in to the AC outlet in my garage? I don't want to leave the trunk open ass the light will drain the battery. What is the best maintainer to buy?
Any help will be appreciated.
Any help will be appreciated.