What Size Solar Panel Do I Need to Keep RV Battery Charged?

What Size Solar Panel Do I Need to Keep RV Battery Charged?

RV offers an adventurous nomadic life without sacrificing comfort or freedom. You can explore and enjoy the country's beautiful landscapes with your home on wheels. Subsequently, the RV's battery plays the most crucial role in ensuring comfort by powering the necessary appliances.

Therefore, keeping it charged for a smooth and worry-free ride is essential. Keeping it charged helps power basic systems, including ventilation, kitchen appliances, and electronic devices. RV solar battery chargers are the best way to run your vehicle's electrical systems while on the road.

Technological advancements have made solar energy systems affordable and more accessible to adopt. Accordingly, they can cater to any needs, from powering your home to your home on wheels.

In this article, we'll explore various components of a solar energy system for an RV. Moreover, you'll learn how to determine the correct size of solar panels to keep their battery charged.

How Does Solar Energy in an RV Work?

There is little difference in the solar energy systems of a house and an RV. They have the same components but are better designed for portability and size. Most systems are either mounted directly on the roof of an RV or are set up manually for portable systems. Solar energy can be used in an RV in the following ways.

RV Solar Battery Charger

The first thing you should understand is that RV has its own set of batteries to power its electrical systems. They work similarly to regular car batteries that charge by themselves during driving. However, they have fixed capacity, and you can only use them for a short period. It increases the risk of wasting gas or ending up with a dead battery.

Hence, RV solar batteries help to keep them charged and healthy even when you're not using them. They ensure that the RV's batteries do not drain when stationary.

Portable Solar Energy Systems

Portable systems consist of foldable solar panels that you can connect to your RV batteries. They come in different sizes and capacities that range begina 100Wh. Moreover, they can power essential devices and do not require any installation.

bluetti pv200

For instance, the BLUETTI PV200 is a foldable and portable 200W solar panel with a high-efficiency rating of 23.4%. They are effortless to set up and come with a kickstand. They are very durable, with an ETFE coating and IP65 waterproofing. Hence, they are the perfect companions for outdoor camping, hiking, and RV adventures.

Comprehensive RV Solar Energy Systems

A complete system requires professional installation and ensures that your RV's electrical systems are run on solar energy. It is similar to a home installation where solar panels are installed on the RV's roof.

Accordingly, it is connected to the battery with a charge controller and inverter. Moreover, you can entirely depend on them as your RV's primary power source. 

How to Size Solar Panels for RV?

RV solar battery chargers help increase the duration of the electrical systems running without relying on their traditional charging. Therefore, assessing your power requirements to size the solar panels for your RV appropriately becomes essential. Small sizes will not be enough to power your appliances, and large sizes would be a waste of money.

Ultimately, it trickles down to two critical factors.

Identifying Necessary Electrical Appliances

Your power requirement is vastly related to the number of electrical appliances you use daily in the RV. All appliances and devices come with labels stating their power consumption in amps (A) or watts (W). You can easily find out the wattage of an appliance by multiplying it by voltage.

For example, a 100-volt hair dryer may have the label for 12 A. Hence, you can find out the watts by the following formula:

(V)olts x (A)mps = (W)atts

100 x 12 = 1200 W

Hence, the required voltage to power a hair dryer is 1200 W. You can repeat the process of all the devices you use and add them up. It will give you the total wattage you need to power your appliances. Remember to consider maximum surge, the power it requires during startup. It demands it for a brief time before running at a lower wattage.


Portable Power Station
Whether it be small blender, mini rice cooker or small refrigerator, EB3A gets you all covered

Check Discount

Power Usage

The next step is identifying how much power you use during a typical day. You can easily calculate it via online calculators or do it by yourself. However, doing it by yourself can be tricky.

The more straightforward solution is to go for an overnight camping trip and monitor its battery usage starting from 100%. Use the devices you would typically use and ensure that you only use them via the battery, not the engine or generator.

After that, check the battery levels after camping ends, for instance, for two days. If your battery is at 30%, you've used 70% of the battery capacity. Then, you can calculate your amp hours per day using the following:

Battery capacity = 300 amp-hours

Used = 70%

Total usage = 70% of 300 = 210 amp-hours

Usage per day = 210 amp-hours / 2 days = 105 amp-hours per day

Hence, your typical power usage would be 105 amp-hours per day. However, the results only reflect your usage of the battery alone. It will vary if you had the engine running or had a generator to charge it. Therefore, the size of your solar panels must match the energy requirement of all available sources.

Related articles: What Size Generator Do I Need to Run My RV?

5 Off-Grid RV Solar Systems to Keep Your Travel Comfortable

BLUETTI Complete RV Solar System with Batteries Reviewed

What Size Solar Panel Do I Need to Keep RV Battery Charged?

Different solar panels are made of different materials with varying efficiency and capacity. A 200W solar panel will generate 200W only at peak efficiency on a sunny day with no clouds or other external factors. In real-world scenarios, it may only generate over 16 amps. Hence, buying three panels would generate close to 50 amps per hour.

Therefore, you have to carefully consider if solar energy is the right solution for you. It is an effective solution for long days of camping and outdoor activities. Hence, it may not be necessary if you're only driving an RV for road trips.

Accordingly, you can consult the following guide depending on your RV usage and activities. It will help you choose the appropriate solar panel size for your power requirements.

Battery Tending

As explained previously, RV batteries tend to discharge if they're stationary for long periods. They can drain even if you do not use them. Therefore, RV solar battery chargers can be used as battery tenders to keep them charged and help maintain their shelf life. Hence, you can make do with 10-50W solar panels if you are not planning to run any electrical appliances.

Light Use

Depending on the RV and its battery capacity, you can use lights and other electrical systems at night for specific periods. Alternatively, you can power it using the power stored in solar panels for longer durations.

The solar energy system will charge the battery during the day, which you can use freely during the night. You can go for portable solar panels of around 50-100W that will be able to power a few small electrical appliances.

Medium Use

With a higher capacity, you can use RV solar battery chargers to run part of its electrical systems that run on DC. It includes the fridge, water heater, and the ventilation system. Accordingly, you can install an inverter to convert DC into AC to run a few electrical appliances, including laptops and TVs.

Hence, you may require anywhere between 100 and 600W solar panels. Subsequently, you can consider the BLUETTI PV350 solar panels of 350W. They are lightweight and portable, with a high conversion rate. They can produce enough power to run essential electrical appliances.

bluetti pv350

Moreover, they are highly durable and splash-proof with advanced laminated technology and long-lasting ETFE material. Its portability allows you to place it strategically to catch maximum sunlight for better energy conversion. Additionally, you can combine two solar panels to generate 700W.

Heavy Use

As the title states, these RV solar battery chargers can power most of its electrical systems. Ranging between 600 and 4000W, it can power almost all the devices in the RV, depending on your power requirements.

However, it may require professional installation for a fixed system, or you can do it with a portable system. Similar to the previous method, you can buy two or more solar panels to match the energy requirements.

Accordingly, you can consider BLUETTI PV420 solar panels, which is 420w solar panel. Like the other products, it has a high-efficiency rate of 23.4% and is a portable panel. Moreover, it provides fast charging to juice up your battery quickly.

bluetti pv420

The PV420 can capture about 2kWh solar energy with six hours of sunlight under ideal conditions. You only have to set up the solar panels and face toward the sun to enjoy continuous solar energy.

Final Thoughts

To summarize, identifying your power requirements in an RV trip is essential to determine the size of solar panels you need. You must consider the list of primary and crucial appliances and calculate their wattage. Alternatively, you can use an online calculator to check how many solar panels you need for daily usage. Accordingly, you can consider BLUETTI PV200, PV350, and PV420 for your portable solar needs. They offer a high-efficiency rate, and you can carry them with you during camping or other outdoor activities.