Choosing the right size battery for your boat and performing routine maintenance will ensure the optimal lifespan of your battery and will save you money. Check your engine manual for the recommended battery rating. Many boats will need two types of batteries, an engine starting battery and a deep cycle battery for powering navigation, lights and domestic equipment. Dual types are manufactured, but are usually only suited for small powerboats or sailboats.

There are four different chemical types of marine batteries for your boat: wet cell (flooded), gel cell, absorbed glass mat (AGM), which are all lead-acid batteries, and lithium. The type you choose is based on your needs (engine starting versus deep cycle), the capacity and lifespan you are looking for and your budget. 

The most versatile type for marine use is the AGM battery. If you don't use your vessel daily, AGM batteries will hold their charge better than wet and gel cell batteries. Long lifespan, low self-discharge rate and outstanding performance make AGM excellent dual-purpose (deep cycle and engine starting) batteries for boaters.

marine batteries

Battery Tips

  • Stay with one battery chemistry (wet cell, gel cell, AGM or lithium) for all of the batteries on your boat. Each battery type requires specific charging voltages and mixing types can cause under- or over-charging.
  • Never mix old batteries with new ones in the same bank. Old batteries tend to pull down the new ones to their deteriorated level.
  • Disconnect your battery when not in use.
  • Regular maintenance is important as it extends battery life and saves money. Beginning of season – charge and check for connection corrosion. End of season – remove batteries for storage, clean top surfaces, grease terminal bolts and store in a dry, cool area like your basement.

If possible, use solar, wind or water power to trickle charge your batteries (see Renewable Energy).

Lead Battery Recycling – The Success Story

More than 98% of all battery lead is recycled. Compared to 55% of aluminum soft drink and beer cans, 45% of newspapers, 26% of glass bottles and 26% of tires, lead-acid batteries top the list as the most highly recycled consumer product.

Batteries contain heavy metals such as mercury, lead, cadmium, and nickel, which will contaminate the environment if they are improperly disposed of. According to Battery Council International, more than 98% of battery lead can be recycled due to its closed loop cycle. 60% to 80% of the lead and plastic are reclaimed and used to produce new batteries. This keeps them out of landfills, waters and away from the marine environment.

 You can find your neighborhood-recycling agent by zip code.


Green Boating Guide: