Batteries - Sailors for the Sea


Choosing the right battery for your boat and performing routine maintenance will ensure the optimal lifespan of your battery and will save you money. 

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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, AGMs will hold their charge better than wet and gel cell batteries. Long lifespan and low self-discharge rate make AGM excellent dual-purpose (deep cycle and engine starting) batteries for boats.

marine batteries

Battery Tips:

  • For all batteries onboard, stick with one battery chemistry (e.g. AGM). 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.
  • For wet cell batteries, frequently check the water levels and top-off with distilled water as needed. Fill up after charging as water levels during a charge.
  • Disconnect your battery when not in use.
  • At the beginning of the season, charge and check batteries for connection and corrosion. At the end of season, remove batteries for storage, clean top surfaces, grease terminal bolts and store in a dry, cool area.
  • If possible, use solar, wind or water power to trickle charge your batteries. Check out Renewable Energy for options. 

Did you know?

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.