Comparing RV Batteries
RV batteries are the powerhouse of your RV. If you plan to camp off-grid, boondock, or just stay overnight with out electrical hookups you’ll be relying on your battery(s) to run your refrigerator, lights, C02 censor, among other important items. Unfortunately, most house batteries that come stock on your RV aren’t sufficient especially if you like to camp off grid frequently. That means you’ll probably want to upgrade your batteries to better suit your needs. To help you determine the best RV battery we compare the three main types of RV batteries sharing the pros and cons of each and explain why we ultimately decided to go with Lithium batteries for our RV battery bank.
RV Battery basics
The job of an RV battery bank is to power items on your RV that run on D/C power like your lights, water pump, refrigerator (when it’s on propane setting), C02 sensor, slides, or other basic items on your RV. It will not power anything that runs on A/C power like your electrical outlets, TV, or fireplace. If you want to create A/C power from your D/C power from your battery bank, you’ll need an inverter.
Batteries have an amp-hour rating that varies by the type and size of battery you purchase. Amps refers to the amount of electrical current a device draws, or in other words how much electrical current an appliance draws from the batteries to run. The Amp-hours (Ah) tells you how many hours you can run your appliances from your batteries. The higher the Amp-hours, the more energy you can use for a longer period of time before the battery needs to be recharged.
The last important thing to know about batteries is that each battery type has a specific Depth of Discharge (DOD) limit. If a battery as a 50% DOD limit, you cannot use more than 50% of the batteries amp hours without damaging the battery. Essentially, your battery bank’s usable energy is cut in half. A 100Ah battery with a 50% DOD would really be 50 usable Ah.
the Three main types of rv batteries
Lead acid rv batteries
Lead acid batteries have electrolyte levels that require adding water to the batteries as needed. They also have a tendency for the terminals to corrode over time. Beyond the ongoing maintenance they also have the least efficient charge and discharge rates out of the three most common types.
Additionally, lead acid batteries should not be drained below 50% of charge (DOD) and are heavy weighing around 50-60 lbs for one battery.
Pros of lead acid
- Low cost ($25 – $50)
- Readily available (anywhere that sells batteries will have these including Walmart)
cons of lead acid
- Ongoing maintenance like checking water levels and adding water as needed
- Heavy weighing 50 lbs. per battery
- Requires venting giving off toxic gases
- Less efficient charge and discharge rate
- 50% DOD limit, meaning your 100 amp hour battery is really 50 usable amp hours
- # of cycles: 300-500 (at a 50% DOD) that’s around 2 – 3 years.
AGM deep cycle rv batteries
AGM batteries charge and discharge at a more efficient rate than a standard non sealed lead acid battery, but still have a 50% DOD limit meaning a 100 amp hour battery really has 50 usable amp hours. An added bonus of AGM batteries is that they do not require venting and don’t expel hazardous gases like you see with a lead acid battery. They are heavy, weighing around 70 lbs. per battery.
Pros of AGM
- Low cost ($150 – $300)
- Still available in most stores that sell batteries, but not as widely available as a lead acid battery
- More efficient charge and discharge rates than lead acid
- No toxic gases, meaning no venting is required
- No ongoing maintenance
cons of AGM
- Heavy weighing 70 lbs. per battery
- 50% DOD limit meaning your 100 amp hour battery is really 50 usable amp hours
- # of cycles: 800 – 1,000 (at a 50% DOD) that’s around 4 – 7 years.
Lithium iron rv batteries
They are extremely efficient for both charge and discharge and are able to handle a much larger or faster draw from the batteries than AGM or lead acid. Most lithium batteries have a built in battery protection system (BPS) to stop them from overcharging or over-discharging.
Pros oflithium iron
- Light weighing 30 lbs. per battery
- Most efficient charge and discharge rates
- No toxic gases, meaning no venting is required
- No ongoing maintenance
- # of cycles: 3,000 – 7,000 (depending on DOD used) that’s 8-10+ years
- 100% DOD, although 80% – 90% DOD limit is advised.
cons of lithium iron
- Expensive: $850 – $2,000+
- Not widely available in stores. Mostly bought online
monitoring rv batteries
At this point, you may be wondering, “how do I monitor my lead acid or AGM batteries to make sure they don’t drop below the 50% threshold?” Most RV’s, trailers, or fifth wheels, have a “button” that allows you to check your battery levels. This button is supposed to show you the level of charge your batteries are at, or how much juice you have left. We hate to be the bearer of bad news, but that button is crap! It doesn’t give accurate readings, which in turn doesn’t allow you to safely or accurately monitor your battery levels. The good news, you can monitor your batteries more accurately with your charge controller (comes with the solar panel kit), and/or your inverter. While this isn’t a perfect reading of your batteries, it does give you a much more accurate reading than your stock “battery monitor button”.
To get a near perfect reading made specifically for your rig, batteries, inverter, and solar panels you’ll want to get a Battery Monitoring Kit (BMK). Read more about BMK’s here. We don’t personally have a BMK yet, and just go off our solar charge controller and inverter readings to monitor our batteries.
We like to account for only the usable energy in our battery bank. With our AGM batteries, we tried not let our batteries go below 50% of total charge. We consider the 50% mark, “empty” which is around 12.0 volts. We consider fully charged, 13.0 volts. Technically, you can drain your batteries lower than 12.0 volts, but doing so will be detrimental to the health of the battery. Please note, this is a generic chart, and may not accurately reflect your exact set up, batteries, or rig. If you are concerned with the numbers, a BMK might be a good solution for you!
Why we chose lithium batteries for our rv
Our battery bank is 200 amp hours (two 12V 100A lithium iron batteries). It was an expensive upfront investment, that could cost you anywhere from $1,500 – $2,000 depending on the company you went with. The best way to justify the upfront cost of our batteries it so do a side by side comparison of a 200 amp battery bank in both AGM and Lithium batteries.
*If you have a lead acid and are happy with it, please feel free to replace it with another lead acid. However, considering the extensive disadvantages lead acid batteries have, we feel they shouldn’t even be considered as an option for upgrading. Not to mention, the highest amp hour rating we could find at Walmart for a lead acid battery was a 12V 24Ah battery which means you would need 4 batteries to reach 100Ah.
Where to find rv lithium Batteries
If you can’t afford Lithium batteries at this time, consider saving up for them. In the long run they really are the better choice. Ultimately, the best RV battery is the one that fits your needs and budget.
- Intro to RV Solar
- Calculating how much solar you need
- Choosing the Right RV Inverter to Power your Rig
Liz & Dennis
We’re two travel-loving, real estate investing, foodies exploring North America as full-time RV’ers. This blog is where we share our lessons learned, tips and tricks, and favorite places to eat, see, and RV across North America! We hope it helps you find your wanderlust, plan and prepare for RV life, and get out on the road!
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