Back when I was messing with impressionable young minds on a daily basis, we spent close to a week of classroom time on battery design, chemistry, charging, and maintenance. There's a lot going on inside a battery, chemically and physically, and it's really necessary to have a good understanding of what's happening to make an informed decision about how to go about bringing a battery to full charge and keeping it there. That's particularly true of one that doesn't get "cycled" regularly. On a vehicle that sits idle more than it gets driven, it's a good idea to partially discharge and then recharge the battery at least once a month. Turn the headlights on for an hour or so, then connect a low-rate charger overnight. That keeps the chemistry going, and prevents "sulfation" which will drastically reduce a battery's cranking capacity and ability to take a good charge.
Jerry
