The guaranteed length of the life of a battery is defined by the warranty and the length of the warranty is defined by the price. It is a fact that the same battery is labelled in two or three different ways by a retailer and the difference is just the terms of the warranty. If I were in your shoes I would go to Walmart and purchase a group 27 deep discharge, lead/acid battery and check on the warranty terms for the time of full replacement and prorated coverage. Manufacturers have not corrected the incidence on premature failures and that has given rise to the warranty market which you also pay for. The reasons I recommend Walmart are 1) quick turnover (do not purchase a battery showing more than 60 days from manufacturing date. It does them harm to sit on a shelf)
2) price 3) no hassle warranty replacements 4) warranty replacement outlets all over the country. I recommend a deep cycle battery as it will be able to start the engine as well as provide you power when the engine is off. There are a number of things you can do to extend their life, 1) always after use charge back to 100% as soon as possible, 2) maintain the electrolyte level by adding distilled water as needed 3) do not over crank the engine, if it does not start right away figure out what is wrong with the engine. A deep cycle battery is not designed for hard cranking but it would be the best compromise for use in a sailboat. Such a battery will set you back around $75 and should last around 3-4 years if taken care off.
2) price 3) no hassle warranty replacements 4) warranty replacement outlets all over the country. I recommend a deep cycle battery as it will be able to start the engine as well as provide you power when the engine is off. There are a number of things you can do to extend their life, 1) always after use charge back to 100% as soon as possible, 2) maintain the electrolyte level by adding distilled water as needed 3) do not over crank the engine, if it does not start right away figure out what is wrong with the engine. A deep cycle battery is not designed for hard cranking but it would be the best compromise for use in a sailboat. Such a battery will set you back around $75 and should last around 3-4 years if taken care off.
Mostly what Benny said. The key to battery longevity is how it is charged. A cheap battery charged well will last longer than a good battery charged poorly. There are several threads on the Musing with Maine Sail forum on SBO. Check them out, some of the issues discussed seem apply to larger battery banks, but the principles are the same for a single battery, just scale the info down.
A Group 27 battery Marine Deep Cycle battery will be more than adequate. Just remember that "Marine Deep Cycle" is a marketing term. The batteries are basically automotive batteries. While there are only a few battery manufacturers, there are many brands. East Penn (aka Dekka) has a good reputation, all of the batteries sold at NAPA are made by East Penn, or so my local NAPA store tells me.
The key is the charger, a cheap charger and deeply discharged batteries equals a short battery life. Get a good name brand multistage charger. You'll pay more up front than a cheap wally world charger, but the battery will last longer. And Benny is correct, only fill with distilled water.
One last thought, be sure to use appropriate fuses right at the battery terminal. Look for a Marine Rated Battery Fuse holder. It goes right on the battery terminal.Terminal Fuse Blocks - Blue Sea Systems
A Group 27 battery Marine Deep Cycle battery will be more than adequate. Just remember that "Marine Deep Cycle" is a marketing term. The batteries are basically automotive batteries. While there are only a few battery manufacturers, there are many brands. East Penn (aka Dekka) has a good reputation, all of the batteries sold at NAPA are made by East Penn, or so my local NAPA store tells me.
The key is the charger, a cheap charger and deeply discharged batteries equals a short battery life. Get a good name brand multistage charger. You'll pay more up front than a cheap wally world charger, but the battery will last longer. And Benny is correct, only fill with distilled water.
One last thought, be sure to use appropriate fuses right at the battery terminal. Look for a Marine Rated Battery Fuse holder. It goes right on the battery terminal.Terminal Fuse Blocks - Blue Sea Systems
