With many different categories of marine battery, it is essential to use the correct charger.

1. Consider a programmable charger to suit different battery technologies. Other considerations for chargers are short circuit protection, damp resistance, reverse polarity protection, overload protection, charger cooling and the ability to deal with the fluctuation of input voltage. The ability to use the charger as a power pack is also a very useful feature.

2. The advantage of a battery charger that can be used as a power pack becomes evident whilst the charger is connected to mains voltage, either shore-power, or, generator. The charger has the ability to provide the boat’s 12-volt requirements whilst also charging the boat’s battery bank. This means saving the onboard battery supply from cycling, which may help provide an extended battery life.
3. A correct charge for open lead acid, maintenance free, AGM or gel batteries can be produced by a programmable charger, this in turn, will assist battery longevity. Another important point to peruse is the output of the charger. A small 10amp charger will be suitable for the boat with a single battery, but a boat with a battery bank of, say, four 100amp batteries will require a charger that is able to produce enough battery input to charge the bank within a reasonable time.