How To Charge an RV Battery

There are multiple ways to charge your batteries, which is great news for those who use a lot of electricity. Having more than one charging option in your RV is a good idea, especially for those who like to dry camp or go boondocking, so you don’t have to worry about running out of electricity. 

Let’s look at the different ways you can recharge your RV batteries.

How Many Ways Are There To Charge an RV Battery?

Since RVs use a lot of energy to run lights, appliances, and devices, it’s crucial to be able to recharge your RV batteries on the road. Fortunately, there are several options available to keep yourself powered up. 

1. Shore Power

Shore power, sometimes called a power pedestal, is a stationary AC electrical source that you plug into. They usually have plug-ins at most campgrounds and RV parks. 

Since external plugs use AC electricity, they will run your AC appliances directly. Most RVs will have a built-in converter that converts the AC into DC power, recharging your 12V battery anytime it’s plugged into the AC source. 

Should an RV Battery Be on When Connected to Shore Power?

Yes, you should leave your battery plugged in when connected to shore power to ensure that it stays topped up. Anything that uses DC electricity, like your lights and RV refrigerator, will constantly draw energy from it. 

The only exception is older RVs whose converters don’t sense the charge and cut it down to a trickle charge upon total capacity. Over time, leaving it plugged in could overcharge the batteries. However, it could take weeks or months before this happens, so it is only a problem in long-term storage. 

2. Generators

Some RVs have built-in generators that may run on the same propane as your stove. For those with small RVs, portable generators are a fantastic option. 

Generators usually run on gas; others, like the EcoFlow Smart Generator, can run on gas and propane, giving you a more versatile option. 

You can use a generator to charge batteries directly if you have the right connections and cables. Otherwise, simply connect your shore power cord to the generator’s AC outlet to recharge your devices.

3. Vehicle Alternator

The alternator in your RV’s engine will also charge your house battery (which powers your appliances) while the engine runs. It doesn’t charge very quickly, so it’s best suited for topping up rather than recharging dead batteries. This method can also be taxing for alternators, so if you rely on it too much, you may need to replace your alternator. As such, having another option is vital if you go dry camping or boondocking for more than a day at a time. 

4. Tow Vehicle 12V Feed

This only applies to fifth wheels and travel trailers that are towed. In this case, wires connect to your brake lights and signals to match your tow vehicle for improved safety while driving. When wired correctly, this auxiliary power can also provide 12V power from your tow vehicles’ alternator to your fifth wheel. 

The drawback is the wear and tear on your tow vehicle’s alternator. Some tow vehicles have a separate dedicated alternator to avoid this issue. Otherwise, ensure your batteries are charged before you go on prolonged adventures so you’re not unnecessarily wearing down your alternator. 

5. Solar Power

Using solar energy to charge batteries is fast becoming the most popular option. It’s renewable and accessible, so you’ll always have the power you need as long as you have enough solar panels for your RV

Furthermore, once you pay for the kit, the energy is free, so you can keep the cost of living in an RV to a minimum. Great options include EcoFlow’s 400W Rigid Panels for rooftop installations. Suppose you have a small RV or high energy demands. In that case, you may want EcoFlow’s Flexible Panels that attach to curved surfaces, allowing you to maximize your surface area for energy generation. 

It’s important to note you can’t just wire a solar panel directly to your batteries. You must run it through a power hub or portable power station first. 

One of EcoFlow’s Power Kits is a convenient option that makes off-grid energy generation, storage, and usage simple and versatile. You can recharge them in multiple ways, with solar being just one of four methods. They also come with a power hub combining all the necessary wiring and components, handling all inputs and outputs simultaneously, so you don’t need multiple components or unnecessary wiring.   

How Long Does It Take to Charge an RV Battery

How long it takes to recharge your batteries depends on the type you are using, how far they were drained, the charger, and the energy source. 

Lead-acid batteries take much longer to charge than newer LiFePO4 batteries, which can be as much as five times faster. It’ll also depend on your input. 

To get a rough estimate, divide the rated amp hours (Ah) by the amps your solar panels, charger, AC plug, or alternator delivers. For example, if you have a 200 amp hour (Ah) battery that’s completely dead and you charge it with a 10 amp service, it could take up to 20 hours. This is a slight simplification since you shouldn’t and often can’t drain your batteries that low. 

How To Charge an RV Battery: Step-By-Step

Charging RV batteries is easy; just be sure to follow these simple steps. 

  1. Make sure the connections are clean and dry. 
  2. Install your charger in a clean, dry, and accessible spot.
  3. Park your RV on a level spot and put on the parking brake.
  4. Take the cables off the battery leads, negative (black) first, then positive (red).
  5. With lead-acid models, clean any corrosion and top up with distilled water if necessary. 
  6. Plug the charger or converter into a power source. 
  7. Attach the charger cables to the battery (or converter cables) positive first, then negative. 
  8. A light on the charger or your smartphone app (when using an LFP model) will let you know it’s charged.
  9. Turn off the power source and disconnect the battery. 

5 RV Battery Charging Safety Tips

RV batteries are completely safe when used and stored correctly, but you should be aware of the following key tips to minimize any safety risks. 

  1. If you use lead acid batteries, always clean any corrosion and keep them in a vented space since they can off-gas chemicals. Don’t tip them; if the acidic liquid electrolyte spills out, it will ruin anything it comes into contact with.
  2. When using a battery charger, ensure it’s compatible with your model (lead-acid, AGM, or lithium) and the rated voltage and amperage to prevent thermal runaway
  3. Disconnect batteries when your RV is in storage. With lead-acid, you must put it on a trickle charger, while lithium models don’t require as much maintenance. 
  4. Never charge a frozen battery; this can weaken it and cause it to fail. Lithium batteries with a BMS (battery management system) don’t have this issue since they’ll only accept charge when the temperature is safe.
  5. Don’t charge or store at temperatures above 122°F (50°C) to avoid thermal runaway, regardless of your battery type. 

Frequently Asked Questions

Is It OK to Leave Your RV Plugged in All the Time?

It depends. If you’re using your RV constantly, then yes, because you’re continually using power and recharging it. However, you shouldn’t leave it plugged in all winter while storing it, as this could overcharge your battery, ruin it, or even lead to thermal runaway. 

How Many Amps Does It Take to Charge an RV Battery?

It depends on your battery; they should only charge at a maximum of 20% of their amp-hour (Ah) rating. For instance, if you have a 200 Ah battery, common in RVs, you should only charge it at 40 amps or less. 

Can I Charge My RV Battery With a Trickle Charger?

A trickle charger is intended to keep fully-charged lead-acid batteries topped up while in storage to extend their life, not to charge dead batteries. If this is all you have, try leaving it on for 24 hours, and hopefully, it can get you going until you can find a proper charger. 

Final Thoughts

Keeping your RV batteries charged while adventuring, whether on-grid or off-grid boondocking, is essential to avoid interruptions. You can keep your lights and appliances on with a little planning, so always ensure you have at least one means to charge your batteries. If you enjoy dry camping or boondocking, you’ll want to use solar power or a generator backup to avoid running out of energy. 

Using one of EcoFlow’s Power Kits with solar panels will ensure you’re always fully charged. Then, you can relax and enjoy your adventure without worrying about power, no matter where you are.

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.


Please enter your comment!
Please enter your name here