How Long do RV Batteries Last?

I remember when I was a child back in the early 1990’s. I lived states away from my grandparents but nonetheless they would stop by three or four times a year for a visit. Each one of these visits they would pull into our driveway with a full sized motor-home. It was always a sight to see, especially to a kid. I remember exploring their RV and finding it all so fascinating. The concept of being able to live anywhere on the road. To be able to point to a map in the morning and start driving. It all seemed so freeing.

Now that I’m nearly forty I’ve considered buying a recreational vehicle myself in a few years. The kids will be getting older and the wife and I can hit the open road. I’m still a ways out on this dream but the next best thing I can do is write about it, right? In an effort to familiarize myself with RVs and all of their ins and outs I have taken the time to write numerous articles on the topic. After all, there is no better way to learn then to try and teach someone else.

Today’s question at hand is exactly how long will the batteries on your RV last when the engine is not turned on or you are not connected to shore or generator power. Like with many things this isn’t a straight forward or easy to answer question. There are a ton of variables that have to be considered before an answer can be given. In this article I will give you my best estimate on how long the batteries will last but to find the most accurate answer for your specific RV model it is best to either consult the owner’s manual or to even call up the dealership. No one knows their vehicles better then the original equipment manufacturer.

So, How Long Will They Last Dry-Docking?

Earlier I had stated that there are a ton of variables that have to be considered. The first of these is what exactly are you intending to power with your batteries? As you know, there can be a lot of appliances, light switches, electronics, and other items requiring power within your RV. I’ll tell you right now that if you intend to power all of these then you are going to have a bad time. For example, some RVs come with a built-in air conditioner. These air conditioners can be a lifesaver when camping in summer heat. The problem with them is they are by far the most energy consuming appliance you will find in your RV. If you attempt to run an air conditioner off of just your batteries then you are only going to get a few hours of cool air before your batteries are drained. The only way to truly run an air conditioner in your RV is with a generator or by being plugged-in at a camp-site.

To explain this a bit further let us look at the types of power that batteries produce for your motor home. Like most other vehicles on the market today your RV produces direct current (DC) electrical power. This is the power that comes from your alternator and the power that charges your batteries. If this was a standard car this power could charge your cellphone with a USB adapter… but that’s about all it could do.

Cars and RVs do NOT produce alternating current (AC) electrical power. AC power is what you find in the typical home or residential building. This is the type of power that comes from the power grid or a generator. Pretty much everything in your home uses AC power. This includes your air conditioner, refrigerator, furnace, dishwasher, microwave, etc, etc. AC is the lifeblood when it comes to powering your appliances and electronics.

Since RVs have both power sources DC and AC they actually have the ability to share this power. This is done by using a converter. The converter converts DC energy over to AC energy. There is also an inverter that converts AC energy over to DC energy. These converters/inverters allow the power sources to be used on whatever appliance/electronic you wish. The downside here is that the power produced from your batteries (DC) is MUCH weaker then the AC power produced from shore docking or through a generator.

With this in mind you cannot expect to run everything in you RV on just your batteries. It is simply not feasible and you will run out of juice just like what we mentioned previously on the air conditioner example. So, let’s boil this question down further to, ‘How Long Will my RV Batteries Last When Running the Bare Minimum?’ We know that running these extra appliances just won’t work, but now we can determine how long the batteries will last when attempting to power the bare essentials.

These bare essentials are your lights, water-pump/toilets, refrigerator/freezer, and perhaps a television. Anything else and you risk draining the batteries faster then you should. Even the smallest appliance, one you may not even think is a big deal can have a significant impact. For example, a coffee maker seems like it wouldn’t consume that much energy but in actuality it can use between six-hundred to eight-hundred watts. That is just a bit below then a mini-refrigerator. Another ‘got-ya’ are hair dryers. Again, these seem small but they consume up to nine-hundred watts.

Once you have determined exactly what you are going to run the next big consideration here is exactly how many batteries do your RV/motor home come with? This why the answer to this article can be a bit tricky as each make/model can come with different number of batteries as well as different sizes of batteries. In most cases it will boil down to trial and error for your specific motor home.

My suggestion is to do an experiment. Try a dry-dock and watch your battery’s charge percentage. (Perhaps do this at home the first time, just in case.) Most folks recommend recharging the batteries once they reach forty percent. If you let it drop lower then forty percent then you could end up damaging the battery. As long as you keep a watchful eye on the battery’s percentage you should be able to get a feel for exactly how long your batteries will last. That being said, I did promise to give our estimate on battery length.

Again folks, this is an estimate, but in most cases you can see batteries last between two to three days without needing a recharge. This is assuming that only standard appliances are being powered. You could perhaps extend this two to three day limit a bit further if you opted for conserving energy by turning off the water-pump, turning off light switches, etc. But, in essence folks you’ll be able to go around two days, maybe three on your batteries without using shore or generator power.

How Long Will RV Batteries Last Before Needing Replaced?

I realized after writing the title of this article that it could be taken two ways. The first was how long could the batteries last during dry dock? The second question though was how long the batteries could last entirely? We all know that batteries eventually die. It is an inevitability. It will happen. The question in this section though is how long are RV batteries expected to last before needing replaced?

From my research I found that most RV owners replace their batteries after about two years of service. While this seems to be the standard I also read that this could be throwing money away by replacing batteries earlier then they need to. Why replace something that still works? With proper maintenance RV batteries can last up to six years. Yes, six years. That number may seem high, but it makes sense to me. I’ve had the same battery in my Camry since 2015 and have had no issues with it at all.

The most important thing to do in order to prolong the life of your batteries is to recharge them as quickly as possible. If the battery is left dead for an extended period of time crystals can form on the plates of the battery. If these crystals remain without a recharge taking place then the battery is in essence ruined. This crystal forming process is called ‘Sulfation.’ Remember earlier how I mentioned now to let the battery’s charge drop below forty percent? Keep an eye on your battery’s charge and recharge them when needed. Do not let them die.

This next battery maintenance tip catches a lot of RV owners off-guard, but there are quite a few parasitic loads that can drain the batteries on your motor-home. These can be gas leak detectors, clocks, sound systems, circuit boards, or many other things. If not found then you can find yourself with a dead battery. To stop these parasites from draining your battery’s power be sure to switch the battery disconnect switch to off when you are not using the vehicle or it is in storage. This will help to prevent you finding dead batteries the next time you prep your RV for a road trip. For more battery maintenance and care instructions I recommend reading this article from KOA.com . It answered a lot of my questions and seemed to be a good resource.

Conclusion

Going into this article I didn’t realize that this would be a two parter: One for battery length for dry-docking and one for overall longevity, but here we are. Either way, I believe we were able to answer your questions. It basically boils down to using common sense and keeping your eye on your battery’s charge. As far as battery life I would suggest every three to four years. You’re not replacing them every two years but you’re not also not going to the extreme of waiting for six years.

If you are looking for some additional reading on the topic I recommend visiting this RV battery guide from NadaGuides.com. It helped me learn a lot about the topic.

Thanks for reading folks and happy trails,

Alec Johnson

ToughAssTools.com

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