RV Batteries

RVing across the country has always been a dream of mine. I am still quite a ways out from achieving that dream but I know that I will eventually get there. For those of you who are lucky enough to already be doing this I envy you. The world is open to you. All it takes is pointing to a map and driving. The freedom of it is enticing. Like with many things though it is not all fun and games. There are still many questions and topics to learn when it comes to caring, maintaining, and enjoying your recreational vehicle.

In today’s article we are going to take an in-depth look at one of these topics: Batteries. As you know your RV, or motor-home, comes with a battery or batteries. These batteries store direct current energy that power everything in your RV. This includes the lights, the radio, the refrigerator, and even your furnace. Without your batteries your RV loses all of its creature comforts. This is why it is so critical to watch the charge on your batteries and to ensure that they do not get to low. Most people recommend not letting the charge on your batteries drop below fifty percent. When your batteries do drop to that fifty percent threshold you need to know HOW to charge the batteries back up to ninety or one-hundred percent. Let’s take a look.

How to Charge the RV Batteries

RVs, or motor homes, can come with one battery or multiple. Along with that their location can vary by make and model. If you do not know where your batteries are stored please consult your owner’s manual, call a dealership, or worst case canvas around the outside of the vehicle until you determine where they are. Once you have found them then we can begin to look at how to charge them.

To understand how to charge your batteries we must first look at the various ways that your battery can be charged. Throughout my research I have found that there are four main ways to charge the battery. Now as I list these I am going to rank them from best to worst. Some of you may disagree with this ranking, but I believe it is well sourced.

  1. The RV’s Alternator
  2. Shore Power
  3. Generators – Built-Ins & Portable
  4. Solar Power

RV’s Alternator

The most common way to charge your RV’s batteries is the old-fashioned way by using the engine and the alternator. This is the way every vehicle on the road today produces power. The engine creates mechanical force which is converted over to electrical energy by the alternator. In essence your RV, or motor home, is no different then that of a standard car. They both have engines and alternators. The only real difference that you are going to see is that the size and number of batteries. The overall process remains the same.

Using the RV’s alternator to recharge your batteries is widely regarded as the best and most efficient. The alternator produces energy but it also produces direct current (DC) energy which is the exact same type of energy that is stored in your batteries. If you were to recharge your batteries using shore power or a generator then you would have to convert their alternating current (AC) power over to DC power by using a converter. With an alternator you get the DC energy upfront.

When charging your batteries with the alternator it is important to remember that the appliances and electronics that you have on during this time all consume battery power. The engine’s alternator provides DC power which is stored into the battery. This DC power is then converted to AC power using an inverter. The AC power is then used to power your air conditioner, furnace, refrigerator, etc. If you have too many appliances on you could actually end up draining your battery even while your engine in is running. This is why it is important to have most of these off during charging with your alternator. Many people will just turn their inverter off to prevent any battery drain. If you do choose to have appliances on during this time watch your battery’s charge percentage to ensure that it is not only moving upwards but it is at the right amount of speed. If it charging very slowly it may be time to turn off some appliances.

Like with anything, there are downsides to using the alternator charge method. The first is it can take a significant amount of time to get back up to full charge. If your battery is below forty percent you could be looking at eight, nine, or even ten hours to get a full charge. That eight hour window may not seem so bad if you are already on the road and are planning on a long road trip… but if you are staying still at a camp-site for a couple of days then you definitely do NOT want to idle your vehicle for eight hours at a time. So, while using the alternator is one of the most efficient ways to charge your batteries it is not ideal for everyone.

Shore Power

If you are going to be staying put at a camp-site or RV park then charging your batteries with your alternator is not an option for you. I know that you do not want to idle for hours on end and none of your camp site neighbors want that either. Now depending on the park you have chosen they can have what is known as ‘Shore Power.’ Shore power is just the RV term for a power source at one of these camp-sites.

If the camp site does have power it will either be a thirty or fifty amp outlet. The thirty amps are for smaller to medium sized motor homes whereas the fifty amp is for the larger models. Either way, it is a straight power source that will give you all the energy you need to power everything within the RV. This could be your furnace, air conditioner, refrigerator, computer, phones, coffee maker, and whatever other creature comforts that you have with you. NOTE that you can also hook your RV up to your home using a fifteen or twenty amp power outlet. This may take some configuration of your circuit board depending on your home.

The best part is that when you connect to these shore power systems your batteries will automatically begin to recharge themselves. This is done by converting the alternating current (AC) energy that you are receiving from the camp site over to direct current (DC) energy. This DC energy is then stored in your batteries. The downside when using shore power connection is that your charge to the batteries is limited by the capacity of your converter.

As we discussed earlier, the shore power connection gives you access to AC energy, but if your batteries hope to store that energy it needs to be converted over to DC energy. This is where your RV’s built-in converter comes into play. This is also where a possible bottle neck can occur. Your converter has a limitation of how many watts it can transfer from AC to DC at a time. The lower the limitation the longer the charge will take. You are essentially getting unlimited power from the shore connection but if your converter is bottle necked then you could still be looking at long recharge times.

As an example, if your battery’s charge is below fifty percent then you could be looking at over eight hours of charging to get you back up to one-hundred percent. Now, if you are staying at the camp site for a while this might not be a problem. This holds true if you are spending the night. Your batteries will charge overnight and there is no inconvenience. If that eight hour charge time proves to be too long there is another option. You can upgrade your converter. There are converter overhaul kits out there that when done can shrink that charge time down to just a couple of hours. One such example of these can be found on Amazon or by clicking here. Be aware though that these kits can cost upwards to three-hundred dollars. It is up to you if you want to invest to save the time or just wait it out each night for a full recharge in the morning.

Generators – Built-Ins & Portables

Generators rather they be built-in to your RV or are an outside portable unit work much the same as a shore power connection does. They provide alternating current (AC) power and have a thirty amp plug-in that allows you to connect your RV directly. Many motor homes nowadays come with built-in generators. These come in handy as you do not have to do any setup. They are already connected to your RV’s power system and they most likely already use fuel that is built in as well. Depending on the built-in they could use their own propane tank or they could use the same diesel/gasoline that your RV uses for its engine. They are also much quieter then a standard portable generator as they are shielded by an outside compartment in your RV which acts to muffle the noise.

The problem with built-in generators is that they come with the RV during the manufacturing process. What this means is that the built-in RV generator typically only comes with enough energy to power all of the stock features of your motor home. If your RV does not come with an air conditioner and you decided to purchase one then chances are you are going to exceed the wattage limit of your built-in generator. The same example can be said if you try to plug-in a bunch of extra appliances like a coffee maker, microwave, hair dryer, or computers. All of these require power and all of these add to your total power required.

If you are exceeding the power of your built-in generator you have a couple of options. The first is to find an alternative built-in generator that provides more power, that will fit in the same compartment, and that will connect properly. This can be easier said then done. Do some research yourself and also contact the dealer where you purchased the RV from. Chances are they do have recommended generators for power upgrades. The downside here is that this can be expensive. Most things are when going through dealerships. Trust me on this, as I have many years of experience working with dealerships.

The other option here is to go with a portable generator. The same can be said if your RV doesn’t even come with a built-in generator. Portable generators provide the same purpose and also have a variety of benefits over built-ins. Portable generators can be any size you want them to be. You can find some starting at around one-thousand watts all the way up to twelve or even fifteen-thousand watts. You will not want for power. They hook up just like your shore power or your built-in generator connection. You’ll also find that they are significantly cheaper then a built-in model. Our recommended portable RV generator is this model from Durostar. It provides over three-thousand watts and should be enough power for most applications.

The downsides here is that portable generators can be rather bulky, especially the higher up in wattage you go. In some cases they can easily be over one-hundred pounds. The good news is that these larger sizes do come with wheels. It will still be a burden though to haul one of these around with you during each camping trip. Another big downside of the portable solution is the overall noise they produce. In many cases camp sites have quiet areas or quiet times. These are times where portable generators cannot be run. This is done in an effort to preserve the serenity and nature of the camp site.  Some portable generator models can have decibel levels ranging from seventy to as high as one-hundred. They can be as loud as a lawn mower running next to you.

If noise is a problem for you there is an alternative portable type known as an inverter generator. These inverter generators are known to be super quiet. They have a decibel range between fifty to sixty. That can be similar to the sound of rainfall on the low end and about the sound of a dishwasher running on the high end. They are much quieter then your standard portable models. The downside to these inverter units though is their cost. Inverter generators can be significantly more expensive then standard portable units. Our typical recommended inverter generator is this model from Champion. It provides over three-thousand watts… but as you can see you are paying a premium for it.

Another important factor to consider is that when going with a portable generator over a built-in you need to consider what fuel source you will need. I mentioned earlier that lugging these generators around can be a hassle, especially on the larger models… well now you have to haul some fuel with you on top of the generator. The portable models will not use the same fuel that is built into your RV. Generators can handle a variety of fuel sources rather it be propane, gasoline, or diesel. Typically I like to recommend diesel as it is the most efficient and cleanest burning. Whatever fuel you decide on you should look at how long a gallon of fuel will last for your generator. This will give you an idea of how much fuel you need to have stored.

The last thing to mention when looking at portable generators is the size of the generator that you will need. If you purchase a size too small then you are not going to be able to power everything you wish. If you purchase something too large then you are going to be wasting power and fuel. Finding the right size is key. I wrote a separate article on sizing generators for your RVs which can be found by clicking here. I highly suggest reading through this article to ensure that you are buying the right sized generator for you and your RV.

Solar & Wind Power

Over the years solar power has become more and more popular. It is a green an energy efficient way to produce power. It also allows you to go truly off-grid when boon-docking. If you think about it even when you are relying on generators you are still reliant on having a constant fuel source of gasoline, diesel, or propane. With a solar system all you need is the sun. It truly gives you freedom to live that off-grid lifestyle.

These systems come with a set of solar panels which then feeds into what is known as an ‘Amp Controller.’ These are also called ‘Charge Controllers.’ These controllers prevent your batteries from overcharging. For those of you who do not know, overcharging can completely ruin your battery, so it is a good protection to have. When purchasing a solar system there are two types of controllers to choose from. The first is known as pulse width modulation charge controller (PWM) and the second is maximum power point tracking charge controller (MPPT). The MPPT is more efficient and the better choice over the two but it is more expensive, so it is a matter of preference.

Along with choosing what type of charge controller you want you also need to figure out what size charge controller  you need for your application. These sizes, or power levels, are calculated in amps. To successfully charge your batteries using solar power you need to ensure your charge controller has more amps then your solar panels and battery combined. To determine this all you need to do is divide the watts of your solar panel by the number of volts in your batteries. So, for an example let’s say you have 1 twelve volt battery and 100 watts solar panel. The formula becomes 100 watts / 12 volts = 8.33. So, by using that 8.33 number we know that our charge controller has to have amperage of 9 or above. If you had 2 twelve volt batteries then you would multiple the twelve volts to get a number of twenty-four volts and so on and so on.

While the 9 amp charge controller will get the job done in the above example it may be worth your time to invest in a larger charge controller in case you want to increase the wattage of your solar panel down the road. I’ve always been a firm believer that it is better to buy bigger with room to expand then to buy the smallest size and have to end up buying it all over again when it does come time to expand. In this example solar kit from Amazon we can see that it comes with one-hundred watt solar panels and a thirty amp charge controller. This gives you plenty of room to expand your solar panels if you wish to down the road.

There are even some folks out there that have opted for using wind turbines to power their motor-homes. These wind turbines work the same as the solar system. They come with a charge controller as well. The only real difference is that the turbine needs to be setup and they are NOT meant for travelling. Wind turbine power is something I would recommend if your RV is mostly stationary on your land. They are not legal to operate while driving and it can be a hassle to have to set them up each time you stop. This is why it makes the most sense if you are living out of your RV on your land. You also need to ensure that you have enough wind to support it.

Jumper Cables

Yes, yes I know I stated that there were only four ways to charge your batteries. The only reason I put it that way folks is that charging your battery with jumper cables  is not ideal. These are emergency measures if your battery is completely dead. If you do run into this situation you can jump charge your battery much the same way you would with any other vehicle. Park another vehicle close enough to your RV’s batteries where you can safely connect jumper cables. Connect the cables like normal, turn the vehicle on, and let the battery charge.

One thing to keep in mind here is that you should turn off ALL accessories on the RV. This means appliances, electronics, and even your inverter. Turn it all off as you do not want something draining your battery’s power while you are trying to jump it. Once you have the battery charged to a point where it is no longer dead then I recommend moving towards a more traditional charging method rather it be using the RV’s alternator, shore power, generator, or something else.

These traditional methods are tried and true and are best for your RV’s batteries. After all, if this was  regular vehicle you do not charge the batteries all the way to full when jumping your car. No, you give it enough juice from the other vehicle so that you can turn the thing on. Once it is on the alternator takes over and you are good to go. The same principle applies here. Get that initial charge and then move towards a more stable method.

Surge Protectors

Power spikes can be a problem rather you are using shore power, generators, solar power, or anything else. These power spikes can occur randomly and without warning. If left unchecked they can end up damaging the appliances and electronics within your RV. To protect against these power surges it is recommended that you insert a ‘Surge Guard’ between the power intake and your RV. This surge guard prevents the power spikes by only allowing continuous power into your RV. It acts as a guard or stopper and catches those power spikes before they get to your RV. Here at ToughAssTools we recommend this Surge Guard on Amazon. It has nearly five-hundred reviews with the majority being positive.


Well folks I believe we have covered nearly everything there is to know about charging your RV’s batteries. Overall, it is not too complex of a process if you stay on it. Just be sure to watch the charge percentage of your batteries and ensure that you do not drop below that fifty percent threshold. If you do find yourself dropping below fifty you should be OK in that forty to fifty percent range, although it is not ideal. Any lower and you can risk damaging the battery.

One more point I wanted to mention in this before closing the article is that in many cases it can take a significant amount of charge time to go from ninety percent to one-hundred percent charge. If you are pressed for time or just want to move on and not worry about charging you will be fine with that ninety percent number. It will save you time and still get the job done for you.

If you are still hungry for more information on this topic  than  I highly recommend the below articles from other websites. These links helped me a lot when researching for this article.

Thanks for reading,

Alec Johnson


Question Marks

The idea of RVing across the country has always appealed to me. When I was a child I lived many states away from my grandparents but that didn’t stop them from stopping by at least three or four times a year. Each time they would visit they would pull into our driveway with a big old motor home. It is something that has always stuck with me and something I hope to replicate when my wife and I are ready.

To prepare myself for future RV excursions I have been educating myself on the topic. If there is one thing I have learned over my life it is much easier to learn something if you attempt to teach it, or in this case, write about it. Research needs to be done. This research not only helps me learn but also allows me to create this article to hopefully help you as well. Today’s topic is focusing on RV and their batteries. Exactly how long will it take to charge your RV’s batteries up to full power? When should you charge these batteries? What can you expect?

How Long Does it Take?

Before we get into how long it will take to charge your batteries I first want to make the point that you should not let your batteries drain empty before charging. In fact, most folks recommend not letting them fall under fifty percent charge. During my reading I did find that some others stated that forty percent was as low as they were willing to go… but the consensus was fifty percent. To be safe though I would recommend staying at that fifty percent marker. There is a myth circling out there that you should not let the battery’s charge fall below eighty percent… but this is not true. You are fine until that fifty percent marker.

The batteries found within your RV are twelve volt. What a lot of folks do not know is that when fully charged these twelve volt batteries actually come in at 12.73 volts. The reason folks say to recharge when your batteries hit that fifty percent mark is when they reach this point they are now at 12.00 volts. If they fall under that fifty percent threshold their volts also fall under twelve volts. This could result in damage to the battery. An example of this type of damage is that if the battery is left at low charge or is completely drained 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 said it was a fine line between the forty and fifty percent charge number? Well, it all boils down to how many volts your battery measures. If you are at twelve volts at a forty-five percent charge then you are OK. However, if you fall below that twelve volt threshold the a recharge is needed. “Volts on a battery can be measured by using a digital voltmeter. Set the tool to DC voltage and place the red lead on the positive terminal and the black lead on the negative terminal to read battery voltage.” (For more info on this, visit koa.com.)


The important thing to remember here is that there is no magic formula to discover how long it will take to recharge your batteries. There are just too many variables out there that can impact the length it takes to charge. A couple of examples of these variables are:

  1. How low is the charge on the batteries? Obviously it is going to take a shorter amount of time to charge your batteries if they are at seventy percent versus at forty percent.
  2. What else do you have running in your RV that is drawing power? It could be lights, refrigerator, electronics, or anything else. All of these require power and will draw power away from your batteries that need charging. Some folks go as far as switching their power inverter off to prevent any further power draw.
  3. Another big question is exactly HOW are you charging your batteries? There are a variety of ways to do this. We have provided a short list of these options below. They are ranked by the most recommended choice.
    1. Using your vehicle’s engine and alternator.
    2. Connecting to a shore power source at a camp-site. Typically a thirty or fifty amp plug-in.
    3. Connecting to a solar power generator.
    4. Connecting to a built-in or portable generator. Typically a thirty or fifty amp plug-in.
    5. Using an automotive battery charger
    6. Worst case, jumper cables.
  4. Each of the examples above can have different charge rates. The alternator in your RV can send a different amount then a generator can. In many cases generators can be bottle-necked based on the amperage limit of your converter. The converter is what converts the AC energy over to DC energy so your batteries can be charged.

With all of these variables in mind it is impossible to predict exactly how long it is going to take to charge your batteries. That being said we can still do our best here to provide you with an estimate, but it is only an estimate. Now most folks recommend charging your motor home’s batteries when they reach fifty percent charge. With that fifty percent charge in mind we can say that it will take anywhere from four hours all the way up to seven hours. If your battery is below that fifty percent threshold then you could be looking at ten hours or more to fully charge the batteries.

You can speed this charge rate up by reducing the number of things drawing power. Like we mentioned previously, turn off the lights. Turn off anything that is not absolutely necessary. The more you reduce the more power that is able to go towards charging your batteries. An important point to remember here is that batteries drain faster then you can charge them. So, if you have an excessive amount of power demand coming from your recreational vehicle AND you are trying to charge your batteries you may find that it very slow going. This is why many folks opt to charge their batteries overnight as there is much less demand.

From my research I have found that the most recommended approach is to charge your batteries via the vehicle’s engine and alternator. After all, it is a vehicle that you are charging so it would make sense that the tried and tested method that all of our vehicles use everyday would be the standard recommendation. That being said, it is not a recommend if you are camping as you do not want to idle for that long. This is where a generator or shore power connection would come in handy. Some folks swear by using an automotive battery charger, but I would advise against them unless you are in a desperate need.

Often times folks will stop charging once they reach a ninety percent charge. This is done as the amount of time it can take to charge from ninety to one-hundred percent can be significant. Experiment on your own setup but you may be able to reduce the amount of charge time by charging to ninety percent and calling it good. The last point to mention here is that faster is NOT better. A slow and steady charge is best for your batteries, if you rush it, or purchase products that promise a super-fast charge then be weary. If you charge these batteries too fast you could end up permanently damaging the battery.


Like with many things folks there is no clear-cut answer here. There are so many variables that have to be considered that it is difficult to gauge what you and your system’s needs are. The best way to do this is to go out there and try it for yourself. In many cases a controlled trial and error experiment is the best way to discover what is needed. When I say controlled I mean have a back-up plan ready in case something does go wrong. After a few experiments you should have a good idea of what it takes to charge your unit and this will allow you to plan your future camping trips with ease.

I hope this article was helpful and able to answer some of your questions. For some more reading on the topic I suggest visiting a few of the links below:

Thanks for reading,

Alec Johnson



RVing across the country has always been a dream of mine. I believe it is the freedom of it that attracts me. Being able to wake up each morning, pick a direction, and start driving. There are no deadlines, no commitments, just you and the open road. If you get too tired or want to take a break then no problem. Just find a camp site or rest stop and pull right in. In most cases these camp sites have thirty or fifty amp outlets for RVs to plug into as well. This shore power connection gives you all of the creature comforts from home including air conditioners, furnaces, microwaves, coffee makers, and so much more.

But, what happens when you go to make camp and find that there is no shore power available. There is no outlet for you to connect to. While some people run into these scenarios accidentally there are others who seek these situations out. It is known as ‘dry-docking’ or ‘boondocking.’ Basically, it is camping with your RV/motor home without a source of shore power. In these situations there are a few ways for you to get power.

The first and most reliable way is by using a generator. Most motor homes and RVs today have built-in generators that come with the unit. These built-in generators can actually share the fuel source that your RV’s engine uses. It makes for a relatively easy setup. If you don’t have a built-in you can also use a standard portable generator. Whichever option you use here you will have power provided to your RV and it’ll be just like you were at an official camp-site with a power source.

There is another way to get power to your RV though and this is what the article is about, batteries. Most RVs come with two deep cycle batteries that are charged while the engine is on. These batteries are also charged when your RV is connected to shore-power or through a generator running. When the engine is off and you are NOT connected to a generator/plug-in then your batteries can still provide you with some basic power.

The first thing you should know is that batteries are substantially weaker versus a generator or shore power connection. A generator/shore power will give you full power without any trouble. Batteries however will run out of juice. This especially holds true if you have a whole host of appliances and electronics connected to the RV. I wrote a topic the other day about how long RV batteries can last when dry-docking. You can read the article by clicking here, but the short summary is that it can range between two to three days.

Powering a Furnace with Batteries

So the question asked in this article is can your RV’s furnace be run with just the batteries? The furnace is quite a bit different then the air conditioner. Air conditioners are notorious power hogs and frankly just cannot be run on battery power alone. If you tried you may only end up with cool air for a few hours before the batteries are drained. The good news is that RV furnaces are less complex, have less moving parts, and overall use much less power.

Chances are your RV’s furnace is propane based. So, what this means is that the actual heat being produced comes from the propane and not the battery itself. This is similar to how a water heater can still work during a power loss event. The only battery power needed for the furnace is the blower. The blower is just what it sounds like. These are the fans that move the produced heat around the cabin.

When it comes to heating your RV by just using the batteries the typical rule of thumb is that you can get through the night with one battery. If you have two batteries then you can get through a couple of nights. That being said, there are a variety of variables that can throw this off. For example, where is it that you are camping at? Are you in Maine in January? Well then your heater is going to be running constantly and so is the blower. But, if you are in South Carolina in March and need a bit of heat to raise the cabin temperature up to the sixties then your heater/blower will run for a bit, and then turn-off. When the temperature drops the heater will turn back on. This is KEY.

If your heater and blower are running all night without stopping then your battery is going to drain much quicker. But, if your heater is turning on and off again throughout the night as needed then you will end up saving battery power. The other thing to consider here is just how many other appliances and or electronics do you have that are draining power from your RV’s batteries? Do you have a lot of lights on? The radio? Television? Other appliances? Each one of these will drain battery power.

Remember folks that it is very important to keep an eye on your battery’s charge. Watch the percentage. If you start to dip below forty percent then it is time for a recharge. This is why I really have to emphasize to you that a generator, even a small one, are essential when it comes to dry-docking. Even if you do not plan to use the generator it gives you peace of mind. You know that if your batteries do go to low and you need a charge then it is as simple as hooking the generator up and flipping her on. Your batteries will then be charged back up and you can start heating again.


So folks in conclusion, yes your RV’s furnace can run on your batteries. You just need to make sure to keep an eye on your battery’s charge percentage and also have a back-up plan to charge the batteries in case you do go lower then you should. I’ve seen some examples where folks purchase a small two-thousand, or even one-thousand, watt generator. Most RV’s come with a four-thousand watt generator… but these smaller ones will produce enough power to help charge your batteries during these overnights. In some cases folks have installed solar panel systems to give their RV batteries that extra charge they need during the overnight sessions.  Here at ToughAssTools we recommend this twenty-two hundred watt inverter generator from Generac.. It is small, easily portable, and will give you the power you need to charge up.

If you are interested into trying your first ‘boondocking’ trip then please please have a back-up plan such as the generator examples we mentioned above. A trip can go south fast if you find your batteries drained with no way to charge them back up.

I hope this article was helpful to you and stay warm while camping!

Thanks for reading,

Alec Johnson




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.


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



It has always been a dream of mine to own an RV and travel across the country. Like many people I’m going to have wait on this dream until my kids are older and the wife and I can slip away for a few days at a time. Those of you who are lucky enough to cruise across the country stopping at your leisure I envy you. Such freedom. Being able to wake up each morning, point somewhere randomly on the map, and start driving.

It is not all fun and games though. There are always problems and hiccups that can occur when driving and camping in your motor home. One of the most common is not having a reliable power source when camping. Most camp sites nowadays have a RV thirty or fifty amp plug-ins available. When these are available it is as easy as plugging in and then you have power to run whatever you need within your RV rather it be your air conditioner, coffee maker, microwave, etc.

When you arrive at a campsite and discover that there is no plug-in, or if you decide to dry-dock it and camp in an off-grid manner then you are going to need an alternative power source. This is where generators come in handy. The generators, either built-in to your RV or a standard portable one, provide alternating current (AC) power to your RV. Most of the appliances in your RV require AC in order to function.

A common question though is will the generator also charge your RV’s batteries? The batteries in your RV are similar to your vehicle’s batteries. They provide you with the power to start the engine. They provide basic lights. With RVs they also provide some other basics such as water pump functionality and even a small television. But that is about all they can do. You need the generator or the plug-in to power the rest of your appliances.

With RVs and motor homes there are two types of power sources. We covered that generators/plug-ins create alternating current (AC) power. This is just like your home. Everything in your home uses AC to power it. This could be your furnace, air conditioner, refrigerator, water heater, etc. The other power source in RVs is known as direct current (DC) power. DC power is just like what you find in your personal vehicle. This is the power that is generated and stored in your vehicle’s batteries. If your batteries drain completely then you will not be able to start the motor home, just like what happens to a car.

The good news here is that most RVs come with what’s known as an inverter and a converter. The inverter converts the DC energy over to AC energy. The converter converts AC energy over to DC energy. SO, if you have your generator plugged-in and running then you are also generating DC power which in turns charges your batteries. The opposite is also true. If you are driving down the road then you will also have AC power based on the DC power inverting over to AC power.

These two power sources loop into each other so as long as you have one you have the other. That being said, DC power is significantly weaker then AC power. Remember, DC is only powered by your vehicle’s batteries. AC power is powered by either plugging your RV into a power source or by an actual generator. You will always have more power from an AC source. As an example, you could technically run an air conditioner using only your batteries… but your batteries would be drained after only an hour or two of use. If you had AC power then your air conditioner can run indefinitely or until your generator runs out of fuel.


In short folks, yes your RV’s batteries will be charged by your generator. They will also be charged if you are docked at a camp-site or RV park and plugged-in. Either way the batteries will be charged and ready to go for the next day’s journey. Lastly, please note that this article is intended to give advice and informational value only. We here at ToughAssTools are not liable for any damage when it comes to using generators rather it be personal, injury, or property.

Thanks for reading,

Alec Johnson


Driving across the country with your RV or motor home has to be one of the most liberating things that I can think of. Being able to wake up each morning, point somewhere at a map, and start driving. No timeline. No objective. Just drive. When you’re tired you find a spot to setup camp and rejuvenate. It is something that I look forward to in the next ten years or so when my kids have grown. For now though, it is just something that I get to write about. All you folks out there who are doing this should enjoy it!

When you do go on these road-trips with your recreational vehicle a constant question is where can I get power? In most cases if you decide to stop for the night at a rest stop or at an RV park you will find power available. These power sources found at these locations are typically thirty or fifty amp and your RV can plug right in so that you can enjoy all the creature comforts of home such as air conditioning, furnace, coffee maker, toaster, etc. Using these plug-ins is known as ‘Shore Power.’

The question that arises now is how do you obtain power when one of these shore power plug-ins is not available? Or, perhaps you do not enjoy the RV camps or rest stops but instead want complete peace and quiet. While this is great you will still need to find a way to power your appliances.


Before we look at generators lets first look at your RV’s batteries. There is a misconception that your RV’s batteries can power everything within the RV. RV batteries are there as a temporary power source. They are not meant to power large appliances like air conditioners. While they technically can do that, you will drain the battery very quickly. Without a power source you could only run an air conditioner for an hour, maybe two, before the battery dies.

Motor home batteries produce DC power. This is the same type of power that your car produces. When your RV is running it will charge these batteries just like your car charges its batteries. When it comes to RVs this direct current power from batteries is then converted to AC (Alternating Current) power using an inverter. The AC power allows you to turn lights on and run basic things within the RV such as the water pump or television set.

So, now, to answer your question of do you need a generator for your RV? It depends. Do you plan to always have a plug-in available for shore power? If so, then you may not need a generator. Or, will you be RVing in a minimalist fashion? In other words, will you not be using any large appliances such as air conditioners, furnaces, coffee makers, toasters, etc? If so, then you can most likely rely on battery power for an overnight stay. In most cases these batteries can last for a couple of days.

However, if you wish to run more then the basics in your RV then you are going to need a generator. The good news is that most RVs nowadays come with a built-in generator on one of the outside compartments. These built-in generators have a few benefits. The first is that since they are built right into the RV they are most likely tied to the same fuel tank that your RV uses. (Diesel most likely.) This means that you do not have to worry about lugging fuel around with you wherever you go. Just be sure to pay attention to your fuel gauge… you do not want to run out of fuel while camping and be stuck there waiting for someone to bring some more diesel your way! The second beneficial point of these built-ins is that they are built-in and covered with insulation. This insulation helps to dampen the noise these generators produce. A very common complaint at campsites is the noise of generators. In some cases they can reach as high as one-hundred decibels. That is the equivalent of a lawn mower running next to you. Quite loud!

A downside of these built-in generators is that they were built specifically with your RV in mind. While that sounds like a Pro what this means is that the generator is sized to power everything in your RV and not much else. So, if your RV does not come with a standard air conditioner but you have installed one… then your generator most likely will not be able to power it. Or, if you bring in a bunch of additional appliances then your generator may not be able to power them as well.

The solution here is a portable generator. A portable generator can be as big as you want it. They range from a thousand watts all the way up to twelve-thousand watts or higher. They will definitely be able to provide you with the power that is needed. Set the generator about twenty feet away from your RV, turn it on, plug-in, and you have power! Easy as that.

As you can imagine there are downsides of these types of generators as well. The first is that they can be rather bulky and difficult to move. This only increases as the wattage increases. If you decide to go with a six-thousand watt generator then you may find it difficult to move around as it could weigh over one-hundred pounds. Along with that weight you also have to lug around a fuel source for your generator. This could be propane, diesel, gasoline, or even solar. Whatever fuel you decide on though it will have to be brought with you.

The other big con here is noise. These portable generators can be quite noisy. I had mentioned this earlier but they can reach decibel levels between seventy to one-hundred. These louder ones can be as loud as a lawn mower. You can imagine how disturbing this would be to fellow campers. In fact many camp sites do not allow louder portable generators due to noise complaints. There is a solution here though folks. There is a type of portable generator known as ‘Inverter Generators.’

Inverter Generators are known as ‘super-quiet’ generators. Their decibel volume ranges from fifty to seventy. That is about the sound of the dishwasher running in your kitchen. Much different then a lawn-mower running nearby. Inverter generators are overall better then standard portable generators, the only real downside here is that they are much more expensive then the standard units. I won’t get into all of the details of inverter generators in this article, but if you wish to read more on them click here to read an article we wrote dedicated to the topic.


So folks to answer your question, yes I do believe you need a generator for your RV. Even if you do not plan to dry-dock it is always better to be safe then sorry. If you are in a situation where there is no shore power nearby you can rest easy knowing that you have a generator that can power everything up without issue. Even if you are into minimalist RVing… it still makes sense to have a generator with you, just in case.

Lastly, please note that this article is intended to give advice and informational value only. We here at ToughAssTools are not liable for any damage when it comes to using generators rather it be personal, injury, or property.

Thanks for reading,

Alec Johnson


Question Marks

Hello folks and welcome to ToughAssTools.com. Today we will be taking another look at RVs, batteries, and air conditioners. There has been a trend lately of dry camping, also known as boon-docking. This consists of going off-grid for your camping adventures. No power-source nearby. Just you and nature. While this sounds appealing it is not for everyone. Many folks find that they miss the creature comforts of home, such as air conditioning.

This is where today’s question comes from. Is it possible to run your RV’s air conditioner while only on battery power? To answer your question… yes, it is possible. The distinction here though is how long do you want to run your air conditioner? You see air conditioners require A LOT of power to run. If you are running the unit solely on your batteries then at most you are going to get an hour or two out of it, and that is if your power inverter is even big enough to convert your wattage over from DC (Direct Current) to AC (Alternating Current).

With RVs, or motor homes, there are two different power sources. DC is the same type of power that your car or other vehicle produces. This type of power is created by the engine and alternator. It is then stored in your batteries. The other type of power is known as AC. This power is just like what we have in our homes today. Since RVs are a mobile home it makes sense to have both vehicle and home power sources.

Since an air conditioner is a home appliance you are going to need AC watts to power it. There are four ways to obtain AC power for your RV. The first is what is known as ‘Shore Power.’ Shore power is when you are at a camp-site or RV park and there is a thirty or fifty amp power source nearby. All you need to do here is plug-in your RV and you now have full AC power. You’ll be able to power your air conditioner and any other appliance you need.

The second type of power source is using a portable or built-in generator. The generator acts the same as shore power, but it is mobile. In other words, you are not tied down to using a camp-site. You can get AC power as long as your generator has fuel. This is the top choice for most dry-dockers. Another option for creating AC power is storing DC power in your batteries as your RV’s engine runs. Then, when you need AC power, a power inverter runs and converts the energy from DC over to AC. As we mentioned above though, this is not sustainable for air conditioners. They simply require too much power.

The last option to get AC power for your RV is by using solar panels. I’m going to tell you the same though as I did when it comes to battery DC power. There just isn’t enough power provided by solar panels to allow the powering of an air conditioner. You would need a ton of solar panels to make it feasible and no one is going to have the space required for this. If you have your heart-set on using solar panels then you will NOT be using your air conditioner. It is as simple as that.

A Further Look

Let’s look at this a bit further now. Most RVs, or motor homes, come equipped with a standard fifteen-thousand BTU air conditioner. They require around thirty-five hundred surge watts just to start and can take any where between fifteen-hundred to two-hundred watts to continually run the appliance. On these larger appliances, like air conditioners, they require an extra boost of power just to start the appliance up. This is known as surge watts. Once the machine has been turned on and begins to run it moves over to running watts. These running watts are much lower then surge watts. If you do NOT have enough watts to cover the initial surge then you cannot start the appliance. Simple as that.

To power this fifteen-thousand BTU air conditioner you are going to need an inverter that converts the battery’s DC power over to AC power. Some RVs do come with inverters… but the factory installed models are typically only rated to convert between one-thousand to two-thousand watts. To power an air conditioner you would need a power inverter rated at a minimum of four-thousand watts. In some cases, on larger RVs, they have a larger sized air conditioner or multiple air conditioners. So, now you would need a power inverter of nearly seven-thousand watts.

For example’s sake though lets say you have the inverter in place and you have three one-hundred amp-hour lithium ion-phosphate batteries (These are the top recommended batteries for RVs). With all of this in place you would be able to run one fifteen-thousand BTU air conditioner for a few hours before the batteries are drained. It just is not worth it.


In short ladies and gentlemen, if you want to power your air conditioner for your RV you need one of two things. You either need shore power by plugging in your RV directly or you need a generator. There are not other options here. The good news here is that most newer RV models out there come with a built-in generator and if your unit comes with an air conditioner then chances are the generator is strong enough to run the air conditioner. To make this even easier most of the built-in generators share the same fuel tank that the RV’s engine uses. SO, this allows for a seamless setup and gets you cold-air right away.

Lastly, please note that this article is intended to give advice and informational value only. We here at ToughAssTools are not liable for any damage when it comes to using generators rather it be personal, injury, or property.

Thanks for reading,

Alec Johnson