OK one of the most common topics of conversation we have with our customers is the use of a battery charger on their boat.
Are they necessary?
Will they damage the battery?
What size do i need?
Should i leave it on all the time im at the dock even when im away from the boat?
Here's some tips:
Battery chargers are not all created equal, some are designed for intermittent use like what you might buy from the likes of Super Cheap or Repco.They are designed for charging the car battery overnight.
Some are designed to be left on for extended periods of time and they are the type we are interested in,in the marine application.
"Will that type of battery charger damage your battery"? No definitely not, our experience is a properly designed charger like a Ctek or Victron charger will extend the life of a battery over 2x what you might get from a battery with no "smart charge function".
What size of charger? Well the industry standard is 20% of your battery banks amp hour capacity. We say well yes but....If you are only looking for a trickle charger and never intend to use the charger to supplement the draw that may occur when you are using the battery driven loads on board then we say you can aim a little lower at about 3 to 5% with a proviso that you don't expect that charger to cover your entire battery loads should you stay aboard.You may need to supplement with a engine charge up routine.
OK so to recap: Get your self a decent marine smart battery charger.
Leave that charger on when ever your at the dock.
Size the charger appropriately depending on your application as above.