WHAT IT MEANS
Apply a load for a short time or wait longer Fully charged Assume 50% charged Time to recharge Recharge – try not to do it again. boaters’ hands and can encourage them to ruin batteries.
A rule of thumb says that when the charging current falls to about 1% to 2% of battery capacity you can consider the battery fully charged so, on a 4 x 110Ah bank, that would give a tail current of about 4 to 9 Amps. This could take eight hours or more using the alternator, so most people should fully charge at least once a week and the rest of the week settle for charging to about 80%.
With a reasonably balanced system, this will take 3 to 4 hours. Another rule of thumb says that to maximise cyclic life we should never discharge batteries