One of the most critical components of your RV is the 12 volt RV deep cycle battery. Virtually everything in your RV from the lights to the water heater is powered by it. Since the RV battery is such an essential part of the vehicle, it is important to know how to reach full charge using a generator especially when you’re in the middle of nowhere with no access to shore power.
When it comes to how to prepare for full time rv living, or even shorter trips in an rv, these are the kinds of things you want to be knowledgeable about. As you plan your trip, keep in mind all of the RV camping necessities, so that you can have a successful trip and stay in your RV.
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Even if you have RV solar panels or RV wind generators installed to the roof of your vehicle, or reached full capacity with a battery charger, you may still encounter the risk of running out of juice if you have a short battery life, use a lot of energy, or don’t have enough sun or wind production.
The easiest and most practical way to fill your battery when you are off-grid is with a fuel-powered generator. Generators can be used both as a power source for 120 volt outlets and a battery charger to fill up the batteries. Since it is a dual purpose unit and particularly useful in a pinch, we recommend everyone with an RV has a fully functional and charged generator in their vehicle to avoid a disruption or have to end their trip early to connect to a power source.
While a portable generator is not the fastest way to charge your battery, it is the most useful especially when you are traveling off grid or unexpectedly loose power. We put together nine easy steps to charge RV batteries with a generator so you can quickly get back to enjoying life on the road with minimal unwanted disruptions.
Before you begin, be sure to follow all safety precautions for handling a 12 volt battery and portable generator. Make sure that all units are in safe, working order and inspect them for any damages or imperfections that may impact the unit’s functionality. When you are recharging your battery with a generator, perform these tasks in a well ventilated area and wear goggles and gloves to help prevent unwanted, potentially serious injuries. Additionally, it’s best to charge your RV battery when it’s not too cold and not too hot to ensure that it can hold the optimum amount of power. Always refer to the manufacturer’s instructions to help keep you and your loved ones safe when recharging your camper battery.
Before we get to how to charge your RV battery with a generator, we want to address some questions you may have:
Does running a generator charge an RV battery?
Yes, we recommend always having a generator on hand because it can be used in emergency situations as a charger for your RV battery. Although it can take a while to bring your battery back to full charge, if you’re in a tight spot, the generator can be a real lifesaver that will get your appliances back on so you can get back to having fun in no time. Having a generator as a backup, alternative power source will help ensure you don’t have to disrupt or end your adventures early and find a town or campsite to plug in.
What size generator do I need to charge my RV batteries?
Typically, a generator will need about a 3,500 watt capacity and 8 amp power to fully recharge your 12 volt RV battery. However, a generator with a 4,000 watt capacity can be useful in charging your battery more quickly. When charging RV batteries, it is important to monitor them so they do not over charge or overheat which could cause permanent damage to your battery. Be sure to check your battery specifications to make sure you select the best RV generator for your unit.
What methods can I use to power my RV batteries?
You can charge your 12 volt batteries with an alternator, or using a generator, solar panels, wind generator, battery charger, or plugging it in to a shore power source. Each method has its pros and cons, so be sure to fully understand the pitfalls of each and determine the best solution to get your camper batteries fully charged especially if you tend to venture off grid.
How do I charge my RV battery with a charger?
Charging an RV battery with a three or five stage battery charger provides a fast and effective charge when connected to shore power or the electricity from your home. It starts charging the RV battery at a higher amp level until it reaches about 80% capacity at which point it transitions to a lower and lower amp charge to optimize the battery life until it reaches the maximum capacity and is fully charged. This type of charger is a great, long term solution for charging and maintaining your battery’s life during winter months or when you are not using your RV regularly. There are less expensive charger options that do not monitor the battery levels. While this is a great budget-friendly option, unless you keep a close eye on the battery charge level, the battery can become overcharged and may eventually become damaged or hold less juice.
How long do I need to run a generator to charge RV batteries?
The best answer: it depends. If your RV battery is down to 20% power, it can take up to ten hours to fully charge. Additionally, the capacity of your batteries, the output of your generator, how many appliances you have running, and the number of batteries you are charging all impact the amount of time it takes to fully charge your RV battery. If your battery is almost full, it could take just two hours to return to full capacity.
How often do I need to charge my batteries?
In general, you should be charging your batteries with a battery charger before you set off on your RV adventure. Using a charger before you venture out will ensure you have full access to your appliances and help ensure they are functioning properly. Once you begin to actively use the appliances that rely on your RV battery, you may need to charge it after about 20 hours of use. However, depending on the age and condition of your RV battery, you may need to charge it more or less than that. If you have a battery bank set up, it may require less frequent charges. Using a battery monitor and observing your usage will help determine the best time to charge RV batteries based on your needs.
How can I extend the power life of my battery?
By regularly cleaning and maintaining your battery and not overcharging it, you will ensure the battery is in the best condition and provide the maximum power time for your vehicle. If you want to spend less time charging, a battery bank can be a useful addition to your setup. A battery bank is two or more batteries that are connected to each other and provide more power to your RV than a single battery can provide. To safely bank batteries, the two batteries must have the same voltage and amp rating, be identical in brand and model, and be about the same age.
When do I need to buy a new battery for my RV?
An RV battery can last a few years up to almost ten years depending on your usage and maintenance habits. To help keep your batteries in their best working condition and help potentially elongate their lifespan, avoid storing batteries in extreme heat or extreme cold, try and prevent the battery from fully losing its charge, and be sure to perform regular battery maintenance according to the manufacturer’s instructions. Depending on your maintenance schedule, usage, and the type of battery you have, the unit may last only 400 charges or up to 5,000 charges. It is wise to get an RV battery monitor so that you can have peace of mind by keeping track of battery charge.
Here are nine simple and easy-to-follow steps to charge a deep cycle RV battery with a generator:
- Before you set out on your RV adventure, make sure your portable generator has enough juice to fully charge your 12 volt RV battery (or to charge it enough until you can make it to another power source). Check to see if you need to top off the gas or oil level.
- Turn off your RV and engage the parking brake to help prevent potential injuries during the battery charging process.
- Unplug and turn everything off inside the RV. Doing this will help your battery charge faster and more efficiently because no appliances are using the power your battery needs.
- From the battery, remove the black (negative) cable followed by the red (positive) cable.
- Check your RV battery for dirt, grime, cranks, leaks, corrosion, or any other potential issues. Clean away any foreign particles and make sure the battery is in a safe and usable condition. If it is damaged, be sure to repair it before using it again or replace it.
- Pop open the fill cap and check the battery’s electrolyte level and fill with distilled water to the fill line if needed.
- Reattach the cables to the battery attaching the red cable first followed by the black. If necessary, use a wrench to securely refasten the cables.
- Connect the RV plug to the generator to charge the battery.
- Be sure to monitor the battery as it charges to make sure it does not over charge which can negatively impact the battery’s performance or lifespan.
Do you have any tips on expanding the lifespan, charging, or maintaining your RV battery? We want to hear from you, so tell us about them in the comments.
Sadly, I do not have an RV but this is very useful information. It’s terrible when the battery dies on you. Happened to me a few times on my car.
I had no clue RV batteries can be charged with a generator, Will surely share this with my husband .
This is gonna help us avoid some car battery problem
😊
One of my dreams is to have an RV! I hate road trips and that would make it so much more tolerable for me.
I gained some knowledge here! Next time of our car breaks I’ll be able to contribute. Thanks for sharing the details.
This is such a helpful article for RV owners, thank you for sharing!
I have always dreamed of having my own RV! That dream hasn’t come true yet, but I am not losing hope. This article would be very useful in the future. Having a generator on hand would really be helpful when the need arises.
Oh this is very useful to RV users! I would love to ride an RV and enjoy the outdoors and also try these tips you shared.
Very informative. My husband and I shopping for an RV so this will come in handy for us down the road.
definitely useful and will share with a couple of friends who just rented an rv for travel.. i am tempted but still in two minds about it
This is something I never would have thought about, since I don’t have an RV. But it makes perfect sense, and this is VERY wise counsel to share – especially with so many more people renting RVs this summer so they can have a socially-distanced vacation with their family.
There is a much more simple way to charge your RV battery. Fire up your generator and plug your RV 110 volt shore power cable into your generator. Also, there seems to be a math problem on the amount of generator you will need. A 1200 watt generator will give 1000 watts of constant power. When your on board converter converts this to 12 volts to charge your batteries, this will give you (assuming some loss in the converter) about 90 amps headed to your 12 volt batteries. It will be a very large battery bank that can handle even 50 amps of input. Nobody will need a 4000 watt generator to charge their batteries.
Oops, I’d like to add some things to my post. 1000 watts converted from 110 volts to 12 volts is about 83 amps, not 90. Almost every RV that has a battery also has a cord that can plug in to 110 volt power. This is called a shore power cable. There is a transformer inside the RV that distributes this 110V power to 110V plug outlets in the RV and also converts this incoming 110V power to 12 volts to charge the battery and run the 12V appliances such as lights, refrigerator, etc. The best 12V deep cycle battery can charge at a maximum rate of about 25 or 30 amps, and this amount only when it’s nearly dead. As it becomes more charged, it will accept less power until when it’s charged it can’t take any more power at 12 volts. The maximum rate that most RVs can charge their batteries is at this 25 to 30 amp rate even though many have a pair of 12V batteries. That’s about 360 watts. (Volts times amps = watts) The built in transformer in the RV is a great way to charge the 12V battery, in fact, it’s made for it! Most RVs have a 30 amp shore power plug. This doesn’t mean that the RV can use 30 amps at 110 volts, in fact, most cannot. A large RV with multiple TV sets, stereos, microwave oven, air conditioner, exhaust fans, etc. etc., may be able to use these 30 amps (which at 110 volts is 3300 watts, which is about the constant output of a 4000 watt generator) but this RV will also have a built in on board generator and the way that this RV charges the batteries is that the on board generator starts automatically without the owner doing anything! Enjoy your travels!!
Thank you for your post. Your info was more useful to our situation than any other that I’ve found. I really don’t want to buy an expensive large generator and for sure won’t be able to find room to haul one that big … assuming I could even get it up the steps into the camper.
Very useful information. I must say your blogs are live-savers. This blog will definitely help many Rv owners. Thanks for sharing keep up the good work.
These are all helpful tips. Many RV owners will definitely find this informative.
In emergency situations, you can also use a booster, but the genitor is really a good idea
It’s really such a helpful article for RV owners, this post helpful for me. Thanks for the share.
Oh, this is very useful to RV users, This is such a helpful article. Thank you for sharing!