You can’t risk battery failure on the water – or on the road. Keep reading for the basics about easy-to-use AGM batteries for marine and RV applications.
Absorbent glass mat (AGM) batteries promise reliable power with near-zero maintenance – and superior performance in harsh operating conditions…
… once you know the fundamentals.
And in this post, you’ll learn the basics of AGM batteries for boats and RVs, including:
- How AGM batteries work – and what makes them different
- Which type of AGM battery do you need?
- Key features to consider
- Battery selection basics
- And real-world stories from people like you
AGM Batteries: The basics
Here’s why AGM batteries are near-zero maintenance and don’t need to be watered:
Like recyclable lead-acid batteries, AGM batteries use “plates” (metal lattices) to hold energy-storing chemicals called active material.
The difference is that AGM batteries use fiberglass mats that absorb electrolyte and keep it in place – making them spillproof and eliminating most maintenance. This design also dramatically improves vibration resistance, which can help extend lifespan in marine and RV environments.
AGM batteries provide greater durability, capacity, and longevity. You can also mount them on their sides for more installation options.
Because of enhanced reliability and decreased maintenance, you’ll often come out ahead with AGM batteries despite higher up-front costs.
And they’re 99% recycled – more than aluminum cans. That means less pollution to harm our precious waterways and parks. (Learn more here.)
Which type of AGM battery do you need?
Most recreational vehicles and boats use multiple types of batteries, each optimized for different purposes.
Starter (“cranking”) batteries deliver short, intense bursts of power to start gas-powered engines on boats or RVs. These batteries use more, thinner plates – providing a greater surface area for chemical reactions. Starter batteries excel at quick power delivery but aren’t designed for ongoing cycling (discharge).
Deep-cycle batteries provide continuous, reliable power for appliances and electronics. For example:
- Boats often feature trolling motors, sonar, GPS, radios, fridges, fishfinders, and stereos.
- RVs commonly power lights, fans, kitchen equipment, stereos, laptops, and more.
Some boats use dual-purpose marine batteries for cranking and trolling. This two-in-one option means fewer batteries to buy. But you don’t get the same performance or lifespan as separate, dedicated batteries. Note that these batteries do poorly when deep-discharged (more than 50% of capacity) and are more likely to overheat.
Battery selection basics
- Consider what conditions your batteries will be exposed to – for instance, water, salt, constant vibrations, high heat, and energy consumption from onboard appliances and electronics.
- Check the Cold Cranking Amps (CCA) rating. It’s an essential metric for marine and RV starting applications, especially in colder climates. CCA measures the battery's ability to start an engine in cold temperatures. A higher CCA rating indicates better starting performance in frigid conditions.
- Make sure your batteries are engineered for longer life and offer a comprehensive warranty. (Discover the truth about battery warranties here.)
- Choose a reputable manufacturer that’s been in continuous operation for more years than your warranty. For example, Crown Battery has been in business since 1926. And our CROWN1™ AGM batteries are engineered and robotically manufactured in the USA for superior performance under harsh conditions – making them an excellent choice to power your boat or RV equipment.
Most importantly, ask other AGM battery users and retailers what they say about your manufacturer.
Don’t take our word for it – meet CROWN1 AGM battery users:
Captain Chris Clemons, Professional Walleye Guide on Lake Erie and Owner of Lakeland Charter Service, Ohio, USA
“I have five boats. And I love that I can run these batteries day in and day out – and they’re just that reliable and perform great.
Other batteries in the past years, after a couple of years of use, if you have a cell go down and then you're buying new batteries every couple of years…
And with Crown Batteries, you don't have to do that… They don't fail. And when you're out on the lake and you're coming home in five- to seven-foot waves, and you have six people on board counting on you to get them home safely, you breathe easier knowing you have Crown Batteries powering your boat – especially if you need that GPS to get you home when a thunderstorm's rolling through and you have zero visibility.”
Pippi Peterson, leading RV Living and Travel Expert on YouTube
Pippi Peterson is a MacGuyver-meets-nomad entrepreneur.
She runs her YouTube business from her RV home office… powered by Crown batteries.
In the video below, Pippi lays out:
- Pros and cons of RV life
- Her YouTube strategy to hit 100,000+ subscribers
- Battery selection advice for improved longevity and reliability.
Glen Matthews, Owner of Port Whitby Marine Supplies
“When you finally persuade your spouse to get a boat... if they don’t enjoy it or it’s stressful -- that’s a problem. Boating is all about the weekend, the trip, the family. You don’t want to let them down. But if you’re concerned about your batteries all the time, then you can’t enjoy your time together…
Typically, batteries like this last 5 to 7 years with proper maintenance and care. I have customers whose Crowns have lasted 8 or 10 years. And when people’s Crown batteries finally wear out, they typically replace them with Crown. They aren’t looking to switch to a piece of junk. That makes sales easy for me…
Crown Battery gives boaters peace of mind. They know they can travel with their spouses and families without experiencing breakdowns -- no worrying about capacity, turning off the lights or stereo, or going to port to recharge. That gives them more freedom, comfort, and flexibility.”
Dale Tea, Sales Manager and Co-owner, Town & Country RV Center
“Before Crown, we bought batteries by price – but that was too expensive.
My customers don’t care about their battery – unless it fails.
But I care. Because if I put in a “cheaper” battery, it just won’t last as long.
And if a customer’s RV battery dies, their brakes might not work. Or they’ll lose power during their big family vacation.
My customer will be inconvenienced, they’ll call me, and I’ll have to process the problem and jump through hoops to replace the battery.
Before we switched to Crown, we didn’t skimp on price. But the other batteries still failed a lot more. And that meant more warranty headaches – lots of people, lots of paperwork, and lots of wasted time and money.
Now that we install Crown batteries in all our RVs and tractors (and my kids’ automobiles), I never have to deal with those issues. And they stand up for me.
My customers are happy, their batteries last longer, and I make more money overall.
That’s why everything here has a Crown battery in it.”
Grant Gallagher, Lifelong Fisher and 2nd-Grade Teacher, Fremont, OH, USA
“When I have time off, I’m always fishing. That’s sun up to sun down -- 12 hours a day in the summer.
With my Crown AGM batteries, the power stays high all day – even when we’re on the trolling motor looking for fish with live sonar.
Crown gives me a crisp, clear image on my fishing electronics. Plus, I never worry about running out of power – and with fishing equipment these days, any advantage helps.
And Crowns give me an edge out of the water, too. If you have any questions, they’ll take care of you. Their customer service is straightforward and second to none.
For me, I’m proud that my batteries were designed and constructed here in the USA. I want to purchase dependable products from a company that supports their community.”
Still feel like a fish out of water when it comes to AGM batteries?
That’s okay – your local battery rep or dealer can help you find the right batteries.
