Your Guide to Selecting the Best RV Battery

The RV battery is a critical component of any camper’s power system. RVers need a deep cycle battery to provide a dependable, steady power current over a long period of time, under a variety of conditions. Deep cycle RV batteries are designed to take the regular and deep discharges of power that come from using RV appliances.

But not all RV batteries are created equal. There are four primary battery types found in RVs – flooded lead-acid, gel, absorbed glass mat (AGM), and lithium iron phosphate. Read on to understand which RV battery is the best for your unit, and why we’re so amped up (get it?) about the Bowlus battery system.

Flooded Lead-acid Batteries
Flooded lead-acid batteries are one of the most common types of batteries you’ll find in motorhomes, travel trailers, and 5th wheels. They’re the cheapest of the deep cycle batteries, and are readily available. However, they have lead plates or grids in the battery container, which makes them heavy and bulky. Those lead plates are immersed, or “flooded”, with a liquid electrolyte made of sulfuric acid and water. They typically have a lifespan of two to five years, depending on how well you take care of them.

While they’re commonplace, flooded lead-acid batteries are not an ideal solution for RVers. First, they need regular maintenance, which includes topping them off with distilled water. They also don’t charge quickly, and the total usable capacity is only 30-50%. They must be located in a well-vented area outside of your RV because they can generate dangerous gasses while they’re charging. And you need to keep them charged. Flooded lead-acid batteries will self-discharge over time and if the charge drops below 50%, you could damage the battery. That means you’ll need to keep a trickle charge on them during your camping off-season. On the flip side, you need to make sure you don’t overcharge a lead-acid battery, because that can irreparably damage the battery as well. Because they’re flooded, there’s also a chance they could freeze in cold temperatures; freezing could lead to a cracked battery case and a damaging spill.

Gel Lead-acid Batteries
Also known as sealed lead-acid batteries, gel lead-acid batteries have the same lead plates as their flooded counterparts, but in this case, they’re immersed in a gel. They’re less prone to spills, but they’re not spill proof – the gel is just a little harder to spill than the electrolyte in a flooded battery. They require little to no maintenance, but do need to be vented and overcharging will destroy the battery.

Gel batteries are simply not recommended by most experts for use in a recreational vehicle. The primary downside to this type of battery is that it has less energy density and charges more slowly than an absorbed glass mat (AGM) battery, which we’ll talk about next.

Absorbed Glass Mat (AGM) Batteries
This type of lead-acid battery is popular for RV use, even though it’s typically the most expensive of the lead-acid bunch. The liquid electrolyte in the AGM is absorbed into fiberglass mats, so it can’t be spilled. An AGM deep cycle battery charges about five times faster than a flooded battery, it can’t freeze and it’s maintenance free. Like its lead-acid counterparts, overcharging can ruin the battery. It has a low self-discharge of just 1-3% per month, as compared to the 5% seen in flooded models.

Lithium Iron Phosphate
At Bowlus, we’re big fans of lithium iron phosphate (LiFePO4) batteries – that’s why we put them in our luxury travel trailers. A totally different technology from lead-acid batteries, lithium iron phosphate batteries are the safest and longest-lasting batteries available for RV use. Lithium iron batteries, while more expensive than a lead-acid model, can power your RV for 8-10 years of frequent camping trips. Because they’re made of non-toxic materials, they don’t need to be vented; we nestle the Bowlus’ LiFePO4 battery safely inside the shell.

LiFePO4 batteries have a wider range capacity than traditional lead-acid batteries in terms of both usable capacity and cycle life. They provide six times the useful power of other systems, with a whopping 80-100% usable capacity (compare that to the typical 30% you get with a flooded lead-acid battery). They’re fast charging, maintenance free, and because they’re not filled with lead plates, they’re about a third of the weight of a lead-acid battery.

We mentioned earlier that anything below a 50% charge and you’re going to damage a flooded lead-acid battery. Well, with a LiFePO4 battery, you can discharge it to about 20% of the battery capacity without damage. You also don’t need a trickle charge on your battery during winter storage – they can hold their charge for months!

Every Bowlus Endless Highways Edition has a 4KWh lithium iron phosphate (LiFePO4) battery (the Terra Firma doubles this to 8KWh), and it isn’t your typical off-the-shelf variety. Manufactured to European specifications, the battery we use is industrial strength. It charges quickly, so you can fully recharge your batteries in just a few hours. We pair it with our integrated power management system that’s designed to power your Bowlus far more effectively than a plug and play system you’d find in the aftermarket.

Our battery system means you can spend up to a week off-grid without a generator. During that time you can run the microwave and the refrigerator. You can even run the highly efficient air conditioner for up to two overnights, something you’d be hard pressed to do with a lead-acid battery. The 3,000 watt pure sine wave inverter in the Terra Firma and Endless Highways Performance Edition (2,000 watts in the Endless Highways Edition) uses the battery to power all the outlets in the trailer, not just a select few. Plug things in just like you would at home. You can charge your devices even when you’re boondocking in the middle of a national forest.

Bowlus’ Best In Class Power Management System
Back in 2016, we were the first travel trailer manufacturer to develop an integrated power management system utilizing the LiFePO4 technology. We use best in class battery chargers and our inverters are the same as those commonly found in solar systems. The system intelligently manages itself so you can occupy yourself with the adventure of the day, not the status of your battery.

The Bowlus power management system continuously analyzes the demand for power and the power available from both the battery and shore power. Sensors in every battery cell communicate voltage and temperature to the system. The system has integrated cell balancing and cell monitoring for optimum protection, and the battery management system will automatically disconnect to protect the battery in case of under voltage, over voltage, or over temperature.

The system includes some exclusive technologies too:

• Power Assist can boost the power in your RV so that you can run the AC and your hair dryer at the same time, even if you’re only hooked up to 15 amp shore power.
• Charging Assist can dynamically adjust battery charging to protect the battery, just like your electric vehicle does.
• Integrated Solar and Integrated Vehicle Charging ensures the LiFePO4 battery will be correctly charged from the optional solar panel and the tow vehicle, respectively. It does this by automatically connecting and disconnecting from the charging circuits as necessary.The battery management system protects your battery when you’re camping in cold weather. Lithium iron phosphate batteries shouldn’t be charged when they’re cold. The system allows power to flow from the battery, but won’t allow it to start charging until it’s warmed up inside the RV. With the battery located in the shell of the Bowlus, this happens in no time thanks to our powerful heating system that can run on either propane or 12-volt. Once it’s over 32 degrees in the unit, the battery will begin to charge at its full rate.To make sure all of this cutting edge technology is user friendly, there’s an easy to use control panel in the RV. You can also connect to the system via Bluetooth and monitor things from your phone. The system even alerts you if the batteries get low.

  Can you see why we love lithium iron phosphate batteries? With the total flexibility and reliability they provide, why would you want to use anything else?