RV Battery Basics: Lead-Acid, AGM, and Lithium
Everything you need to know about the most common types of batteries found in modern campers.
Image Caption: Photo Credit: Getty
When it comes to powering your rig, choosing the right RV battery is crucial—they power your lights, refrigerator, water pump and other electrical components when you’re off the grid. There are three primary types of 12-volt batteries commonly used in RVs: lead-acid, AGM (absorbent glass mat) and lithium. Each has its advantages and disadvantages, making it important to understand which fits for your needs.
Photo Credit: Getty
Lead-Acid Batteries
The oldest and most common type of RV battery uses lead plates submerged in a sulfuric acid solution to create an electrochemical reaction. These are usually the cheapest option upfront, making them attractive for budget-conscious owners, and they obviously have a long history of reliability and performance. They’re easy to find.
Good to know: Lead-acid batteries are relatively large, heavy and typically last between three and five years, especially when subjected to deep discharges. Regular maintenance, such as checking fluid levels and cleaning terminals, is required to ensure the battery operates efficiently. Deep discharging (draining the battery to a level below 50 percent) can significantly reduce the lifespan of a lead-acid battery.
Photo: Odyssey Battery
AGM (Absorbent Glass Mat) Batteries
This type of sealed lead-acid battery uses fiberglass mats to absorb and hold the electrolyte, preventing it from spilling. These products offer many of the benefits of traditional lead-acid batteries, but with some key improvements. AGM batteries are sealed and do not require the regular maintenance that traditional lead-acid batteries do. They can recharge more quickly compared to flooded lead-acid batteries—a huge benefit when you’re on the go. AGM batteries are more resistant to vibrations, making them ideal for RVs that travel over bumpy roads.
AGM batteries are designed to handle deep discharges better than traditional lead-acid batteries, providing more usable power. Because the electrolyte is absorbed in the glass mat, there’s no risk of spillage or leaks, even if the battery is tipped over. AGM batteries generally come with a higher price tag than traditional lead-acid options. Although they’re lighter than flooded lead-acid batteries, An AGM RV battery can still be heavy and bulky compared to lithium power cells. AGM batteries typically last around five to seven years, which is shorter than lithium options.
Photo Credit: Battle Born
Lithium Batteries
The newest and most advanced type of RV battery uses lithium iron phosphate (LiFePO4) chemistry, more efficient than the lead-based chemistry of other batteries. Lithium batteries can last 10 years or more with proper care, significantly longer than lead-acid and AGM options. Lithium batteries are much lighter than lead-acid and AGM batteries, and store more energy, making them easier to handle and more space efficient. They have a deeper depth of discharge (up to 80-90 percent), so more of total capacity can be used without damaging the battery. They require no maintenance. Lithium batteries charge more efficiently and quickly than traditional batteries.
The biggest drawback of lithium batteries: high upfront cost, sometimes significantly more than lead-acid or AGM batteries. Lithium batteries require a specifically compatible charger, which can add to the initial investment (although many RV power converters or inverters have a lithium charging setting along with lead-acid). Lithium batteries can perform poorly in extreme temperatures, especially very cold conditions. However, some lithium batteries come with built-in temperature management systems to mitigate this issue.
Conclusion
This choice comes down to your priority: cost, longevity, performance or weight. Lead-acid batteries are a budget-friendly option, but provide less power, need more maintenance and have a shorter lifespan. AGM batteries offer a nice balance between performance and durability, with the added benefit of being maintenance-free. Lithium batteries stand out for longevity, efficiency and light weight, but cost more. Lead-acid is all you need if you usually camp connected to campground power. Lithium are best for long-term boondockers who camp off-grid using solar power or generators. AGM is probably best for folks who camp off-grid only occasionally.
Got more questions about your RV battery or another topic you’d like to see covered by our vehicle expert Ken Freund? Drop us note at [email protected].
This article originally appeared in Wildsam magazine. For more Wildsam content, sign up for our newsletter.
