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How to Find the Right Battery Charger for Your Boat

Power - by Bryan Veldboom - updated on 3/29/2023

X2Power battery and marine charger

The sun is out and you're ready for a pleasant weekend on the water, but when you go out to your boat, you discover you've got a dead battery on your hands. A reliable battery charger is crucial to maintaining your marine batteries. If you're in the market for a new marine battery charger, you'll find plenty of options at Batteries Plus. Before picking one up though, it's important to understand a few basics first. Today we'll be tackling some common battery charger questions to help you find the right one for your needs.

What to Look for When Buying a Battery Charger

Make sure your Marine Charger Matches Your Battery's Voltage

  • It's vitally important to select a charger that matches the voltage of your battery.
  • Using the wrong charger can harm your battery, forcing you to replace it prematurely.
  • For marine batteries, 12-volt batteries are standard, although both 24-volt and 36-volt batteries are sometimes used as well.

Make Sure Your Marine Charger is Compatible with Your Battery's Chemistry

  • Be sure that the charger you select has a setting that matches the chemistry of your battery.
  • Using the wrong charger can damage your battery.
  • Marine batteries come in 4 different chemistries: flooded, AGM (Absorbed Glass Mat), gel and lithium.
  • If your starting and deep cycle batteries have different chemistries, you will need to pick up a different charger for each battery, or find a charger with a charging setting for both chemistry types.

Do I Need a Special Charger for a Marine Battery?

No, any charger that matches the voltage and chemistry of your marine batteries will work fine. The main advantage of marine-specific chargers is that they're often water resistant, which allows you to mount them permanently to a battery housing on your boat. Read our blog "How Does an Onboard Battery Charger Work on a Boat?" for additional information. Here is a list of Onboard marine chargers available at Batteries Plus:

How Long Does It Take to Charge Your Marine Battery?

In order to determine how long it will take to charge your battery, you'll need to know two things:

  • The amp hour (Ah) rating of your battery - measures how much amperage a battery can provide per hour (This can typically be found on the manufacturer's website).
  • The amperage of the charger you're using (this can be found in the owner's manual or on the outside of the charger itself).

Once you have this information, you can determine the charging time using this equation: Battery Ah Rating ÷ Charger Amperage. For example, a 75Ah battery using a 7.5 amp charger will take roughly 10 hours to fully charge.

Can You Overcharge a Marine Battery?

Overcharging will harm your battery, so you need to be sure this doesn't happen. There are two ways to prevent overcharging.

  • Monitor the charging process to prevent your battery from overcharging.
  • Pick up an automatic charger with a float mode that will shut off automatically.

What Causes Battery Undercharging?

Allowing your marine battery's charge to drop too low is equally bad. Here are a few tips to follow:

  • Charge your marine battery after every use.
  • If your battery isn't being used very often, you'll want to charge it every 30 days.
  • A good rule is to keep the batteries on a charger overnight to have them charged up and ready for the next day.

Find Replacement Marine Batteries & More at Batteries Plus

Your neighborhood Batteries Plus has plenty of additional boating essentials, including:

Need a new boat battery?

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