Originally Posted by Mercury
I think I am going to need a new battery soon, it's for my Brown band 50hp. Mercury it has leccy start & power T&T. has any one got any recommendations? Will an ordinary car battery do the job, or is there such a thing as a boat battery? and if there is, are they any different. Cheers.
Lots of differences; you need to have an idea of what the battery is supposed to do before deciding on which you need (or, alternatively, which you can do without.)
Marine Deep Cycle batteries (I assume that's what you guys are calling leisure batteries?) are built with thicker, less-foamed plates, and are designed to be drained down to a low percentage (30%?) of capacity without harm. They typically have cycle lives of about 1000 or so. This is what you need if you spend long hours with the motor off, but lights, TV, stereo, blender, and electric massage chair running.
Starting batteries are less tolerant of deep discharge, preferring less than 25% discharge or so. If all you use your battery for is, say, an anchor light and your VHF for a few hours, plus starting duties, then you can probably go with one of these.
Dual purpose batteries are built somewhere in between, but are (my opinion) closer to starting batteries than deep cycle batteries.
Biggest factor in longevity is, I think, care. Make sure you don't drain them down below their minimum charge level (causes sulfation), and make sure your charging system doesn't fry them (for external charging, a good three-stage smart charger is a wise investment.)
A search for "Battery Primer" should get you more info than you care to read.