Most RVs come with deep-cycle 12-volt or 6-volt lead-acid batteries that power up a variety of electrical gadgets. The batteries must be constantly charged even when the RV is not in use.
Plugging into a power source like a generator or campground electrical hookup is the fastest way to charge RV batteries. However, this is a good option only if you have a generator or developed campground. Otherwise, there are several other ways to give your RV battery some juice without a generator or shore power. Dive in for more details on the fastest ways to charge RV batteries.
While many people think RV-ing is about disconnecting from technology and roughing it on the roads, parks, or wilderness, there are still many electrical appliances in RVs. These include a water heater, refrigerator, furnace, lights, carbon monoxide detector, portable air conditioner, and more.
While it might seem obvious, many of these electrical products are powered by a 12-volt DC power battery. Some RVs have larger electrical appliances such as TVs or other kitchen appliances, and these would run on the RV's 120-volt AC system.
Like any battery, after a while your RV batteries will need to be charged. Keeping them charged to the manufacturer’s recommended percentages helps prevent any permanent damage to the battery. As a rule of thumb, you want to always keep deep cycle batteries charged above 50% and lithium batteries above 20%. You can learn more about the difference between deep cycle and regular batteries here.
There are various ways to ensure your batteries are always charged above the recommended percentages, these include: as trickle charging, alternator charging, using green power, or connecting to an electrical outlet.
Here is a look at each of them individually.
Probably the slowest way to charge your RV batteries is via trickle charging. This method is best used to keep your batteries charged while they’re in storage for the winter. If you plan to park your RV in a remote area and head home, simply pull out the RV battery and bring it with you so you can trickle charge it.
The battery will start self-discharging if you leave it in the vehicle. Usually at a rate of 4 percent per week. Bringing it home and connecting it to a trickle charger such as a battery Tender will help keep it recharged and ready to use. This will help extend the battery life. Plus, it's safe at home from thieves who usually target RV batteries.
You can check out our guide on the best solar trickle chargers for RVs or motorhomes here.
You can also charge your battery while on the move by either using your RV’s own alternator or that of a vehicle you may be towing. In most models your alternator should charge your batteries automatically. However, this process is just as slow as trickle charging.
Alternators simply aren't very quick. While they may be able to recharge primary batteries after the vehicles start, their main job is running the electrical circuits. This means using a tow vehicle alternator to charge a fully depleted RV battery is a slow process because the alternator is already working to keep the tow vehicle's own battery fully charged.
This might not matter to you if you’re planning an extended road trip. However, if you’re already settled in your camp site, then this option might not be the best option.
It is possible to boost your alternator’s charging capacity by installing a DC-DC smart charger. These types of chargers analyze your battery size and type, then take power from the alternator and convert it to an amperage suitable for topping up the battery fast. Or at least faster.
Green Power Sources (wind, solar panels)
Here at Sunvival we love to recommend using alternative and FREE power sources such as wind and solar. After all, RVs allow their owners to travel and camp where the weather is nice, so why not take advantage of Mr. Wind and Ms. Sunshine? Although, between the two, solar is the more popular.
If you like to fully immerse yourself into the wilderness and disconnect completely from the grid, then green power might be your only option to keep your batteries charged.
Solar panels for RVs are available in a range of sizes and are valued depending on how many watts of electricity they can produce. Larger RVs require more solar panels and enough roof space to accommodate them.
Unfortunately, you can’t just connect your solar panels directly to your RV battery. Your solar panels must first be wired to a solar charge controller which then can connect to the battery. This method is a little costlier that the others due to the extra tools needed, plus having to learn how to properly wire the system together.
In terms of speed in charging your battery, well that depends on various factors. How sunny is it outside? What’s the surface area of your solar panels? Are you in the shade? If you need help deciding what to look for in solar panels for an RV, please visit here.
Another thing to remember is that you will need a DC to AC inverter in order to power most of the electrical appliances in your RV. Even so, a solar system might not be strong enough to power heavy energy consuming appliances such as an air conditioner. But since you are RV-ing somewhere lovely, you can just step out for a breather, can't you?
Connecting to a Generator or Shore Power
The fastest way to charge your RV batteries is by connecting to either a generator or shore power supply. It might also be the easiest since all you have to do is plug your RV power cord to the power source. While it all sounds easy-peasy, there are a few things to consider before connecting your RV.
Outlets at campsites are usually exposed to the elements. As such, its important to check the polarity of the outlet. A reverse polarity can happen if the neutral wire is connected to the hot wire. This means that there is always electricity flowing out of the outlet even if an appliance is off.
Long story short, this can cause some serious damage and fry your appliances. So we recommend using a polarity tester to help determine if the outlet is safe. They can be pretty cheap, so definitely worth it.
Additionally, to preserve the electrical system of your RV against harmful power surges, you should consider getting a surge protector. Electrical Management Systems (EMS) can also help in protecting your RV from spikes or brownouts.
NOTE: a spike is a sudden increase in electrical voltage above the designated level for a circuit. On the other hand, a brownout is a decrease in voltage.
If there are no shore power hookups, you can use your generator. Most large RVs already have a propane-powered generator installed, but you might need to buy one separately for smaller RVs and travel campers.
After turning the generator on, make sure to give it a few minutes to warm up before plugging it to the RV.
If you have a 3000-3500 watts generator, you can produce enough power to support larger, everyday equipment such as HVAC systems, TVs, and refrigerators. The RV’s converter will convert the 120 volt AC current to 12 volt DC current so the battery gets charged.
BTW, did you know that there are solar generators? Here we describe the difference between a gas generator and a solar one.
All in all, plugging into either shore power or a generator is the fastest way to charge RV batteries. However, when using a generator, you must be prepared for the high cost of propane, the noise as well as the smell of fuel.
Other things you need to know about RVs electrical system
While knowing different ways to charge your RV battery is good, you also need to know a few other things about other RV power tips and safety precautions. These include:
Determine how many appliances you can have plugged in at a time
RVs have many electrical appliances. The amount of electricity consumed by each appliance you plug in varies. While some gadgets are heavy users, others operate pretty well on little amounts of power. The majority of the appliances in your kitchen are energy-intensive. Your toaster, coffee machine, and microwave all use a lot of electricity.
Additionally, air conditioners use a lot of power. Other appliances that use a lot of power include curling irons, hair dryers, and showers. It would be best if you didn't operate too many energies intensive appliances simultaneously. This is especially true for power cords rated at 30 amps.
Use the amps by volts product (Amps * Volts) to know if you are overloading your system. This product is called watts. Your circuits will function properly as long as you don't exceed the wattage limit.
Two small capacity batteries are better than one big capacity battery.
RV's 12-volt DC system requires one 12-volt battery or numerous 12-volt batteries connected in parallel. However, it is usually preferable to use two 6v batteries connected in series to form a 12-v battery rather than just one 12v battery.
You will typically have a significantly longer discharge time with this arrangement. Plus, this formation leads to longer battery life. But you must be prepared to create space for two batteries instead of one.
Nevertheless, the trade-off can be worthwhile if your camping requirements demand extra battery life.
Most RVs have two electrical systems, a 12-volt DC system and a 120 volts AC system. Usually, a 12-volt battery powers the DC system. The battery needs to be kept charged. Knowing a few tips and safety precautions about electricity will help keep your appliances safe and preserve your battery life.
The different ways to charge your RV batteries include tickle charging, alternator charging, green power, and using a generator or shore power. Plugging into a generator or shore power is the fastest way to charge RV batteries. You can learn more about RV batteries here.
If you want to learn what is causing your battery to lose charge, check out our guide here.