If you're planning a road trip in your RV, one of the questions that may come to mind is whether your fridge will run off the battery while driving. The answer to this question depends on several factors, including the type of fridge you have and the size of your RV's battery.

In this article, we'll explore the different types of fridges found in RVs, how they work, and whether they can run off the battery while driving. We'll also provide tips for maximizing the efficiency of your fridge and prolonging the life of your RV battery.

Types of RV Fridges

There are two main types of fridges found in RVs: absorption fridges and compressor fridges.

Compressor-Powered Fridge

A 2-way refrigerator, also known as a compressor-powered fridge, can operate on either 12V DC (battery power) or 120V AC (shore power), hence the "2-way" designation. Similar to a residential refrigerator, it uses a compressor to maintain cold temperatures and preserve food.

Advantages of Compressor-Powered Fridge

• Capable of reaching low temperatures and maintaining consistent cooling, irrespective of external ambient temperatures, due to its compressor motor.
• Functions well on uneven terrain, making it ideal for boondocking (dry camping).
• Operates efficiently on battery power, but may require additional solar power as these fridges primarily rely on electricity rather than gas for cooling.

Disadvantage:

• Requires sufficient battery power and/or solar power to operate.

2. Absorption Refrigerators

On the other hand, a 3-way fridge, also known as an absorption fridge, can run on DC or AC power and can also utilize LP gas, employing a heat exchange system to expel warm air and cool the interior.

Note: Some caution against running the fridge on liquid propane gas while driving due to safety concerns.

Advanntages:

• Can function for extended periods off-grid by relying on a gas flow exchange system, though this consumes more propane, it is a more energy-efficient approach.

Disdvanntages:

• When running solely on 12V, 3-way fridges tend to be inefficient and can rapidly deplete batteries. Solar power and DC to DC chargers can help mitigate this issue.
• Due to the gas flow exchange system, an absorption refrigerator must remain level and have proper ventilation to operate efficiently.
• More susceptible to ambient temperatures, typically only able to lower internal temperatures to a certain level below the ambient, unlike a compressor refrigerator.
• Running the 3-way on propane consumes more fossil fuels compared to relying on rechargeable battery power supported by solar energy.

Now that you understand the types of fridges, let's explore the solar components necessary to power your fridge from a battery bank.

Determining Your Energy Requirements

To begin, you'll need to calculate the watt hours necessary to power your fridge. While consulting your RV or vehicle manual for estimated watts or amps is ideal, you can use the table below as a reference. However, note that there are significant variations based on the mode used (AC, DC, LP) for an absorption fridge, as well as the size and style of your compressor fridge.

For instance, if you have a compressor-style fridge running on 12V/DC power directly from the battery, you can calculate the power consumption as follows: Volts x Amps = Watts. Using 12V power at an average of 8.5A, the consumption would be 102W. Assuming the fridge runs for approximately 6 hours, the daily consumption would be 102W x 6 hours = 612 watt hours (WH).

If you have a single 12V-100Ah lead-acid battery in your RV, you have 600 available WH per cycle due to the 50% safe depth of discharge (12V x 100Ah x 0.5 = 600WH). Alternatively, with a 12V-100Ah Lithium Iron Phosphate (LFP) battery, you would have 960WH available per cycle due to the 80% depth of discharge (12V x 100Ah x 0.8 = 960WH).

If your lead-acid battery is fully charged at the start of the day and you have no other means of recharging (e.g., solar, DC to DC charger, etc.), it will be completely depleted by the fridge's energy requirements. However, with an LFP battery, you would have approximately 348WH of energy remaining for other electrical appliances. Learn more differences from AGM Vs. Lithium Batteries: Which Is Better For RV.

Running a Fridge on Battery More Efficiently with These Components

When you are away from an electrical outlet, you can charge your batteries in one of three ways: 1. Solar Panels, 2. Engine Charge (with DC to DC Charger), 3. Solar or Gas Generator.

Each method has its own advantages and considerations. Solar panels are a sustainable and environmentally friendly option, harnessing the power of the sun to charge your batteries. They are quiet, low-maintenance, and ideal for long-term, off-grid use. However, they are dependent on sunlight and weather conditions, so their effectiveness can vary.

On the other hand, an engine charge with a DC to DC charger is a reliable and quick method, especially when you're on the move. This option allows you to charge your batteries while driving, making it convenient for those who are frequently on the road. It's a great choice for maintaining power levels during extended journeys or when you need a rapid recharge.

LiTime 12V 60A DC to DC Battery Charger

Finally, a solar or gas generator provides flexibility in terms of power source. A solar generator offers a clean and renewable energy solution, while a gas generator ensures consistent power regardless of weather conditions. Both options are versatile and can be used in various locations, making them suitable for a wide range of off-grid scenarios.

Ultimately, the choice of charging method depends on your specific needs, the availability of resources, and the duration of time you'll be away from traditional power sources. Each method offers its own unique benefits, allowing you to tailor your approach to suit your individual circumstances.

For extended periods of running your fridge off a battery bank and frequent boondocking, it is highly recommended to invest in high-quality, long-lasting Lithium Iron Phosphate batteries and consider adding a solar array.

LiTime 12V 280Ah Lithium Battery for RV

In general, the most effective time to utilize your RV battery bank to power your fridge is while you are driving, as it continuously receives recharging from your vehicle's electrical system through the 7-way connector. This connector, which powers the RV's exterior lights, brakes, and more, allows a trickle charge (approximately 5A) from your alternator to maintain a fully charged battery bank during travel. For example, if you depart from home or a campground where you were plugged in and your battery bank was fully charged, this trickle charge system is designed to sustain your battery bank's charge while on the road.

Nevertheless, many RV owners have discovered the limitations of trickle charging from the alternator, especially after using their battery for off-grid camping (boondocking or dry camping). Therefore, if you anticipate boondocking more frequently than connecting at a campground, a DC to DC charger will significantly simplify your life. This device takes the trickle charge from your alternator and boosts it to a 20-60A current, depending on the type and size of charger you choose to install. Consequently, it can effectively recharge a depleted battery between campsites, boondocking locations, etc., irrespective of whether you have solar panels on your roof. Refer to type and size of DC to DC Charger for detailed information.

Will Your RV Fridge Run Off Battery While Driving?

The answer to this question depends on the type of fridge you have and the size of your RV's battery. If you have an absorption fridge, it will continue to run as long as there is propane gas or AC electricity available, regardless of whether your RV's engine is running or not. This means that an absorption fridge will run off propane gas while driving, but it won't draw power from the battery.

If you have a compressor fridge, it will only run off the battery while driving if your RV's engine is running. This is because the alternator in your RV's engine charges the battery while driving, which provides the necessary power for the fridge to operate. If you stop driving and turn off the engine, the fridge will no longer receive power from the battery.

How Long Will an RV Fridge Run Off a Battery?

Let's get right into calculating how long an RV fridge can run on a battery. To do this, we use the formula watts/voltage = amps to determine the number of amps consumed by the fridge per hour. An average RV fridge uses around 150 W and runs on a 12V battery, so it would consume 12.5 amps per hour. If the battery has a capacity of 100 amp hours, the fridge could run for about 8 hours before needing to be recharged. The fridge can run for longer if the battery has more amp hours or if the fridge requires fewer watts. Using an inverter may allow the fridge to work, but won't significantly extend its runtime. 

A better option is to use propane gas along with the battery as it generates a current that can keep the battery going for longer without draining. The type of fridge also affects how long it can run on a battery; absorption fridges run for less time than compression fridges. Knowing the type and capacity of the battery is crucial in determining the fridge's runtime.

For better performance of the batteries, we recommend you change your lead-acid batteries to LiFePO4 batteries for their lighter weight, higher energy density, and longer lifespan features. 

 For example, the LiTime 12V 280Ah Plus Deep Cycle Lithium Battery is designed with low-temperature protection, making it suitable for various applications such as marine, RV, home storage, UPS power, backup power, off-grid, and trolling motors.

It comes with a built-in 200A BMS (Battery Management System) that provides comprehensive protection, including overcharge protection and recovery, dustproof, waterproof, and salt spray resistance, as well as low-temperature cutoff protection. It utilizes EV-grade A LiFePO4 battery cells, offering over 4000 cycles of life, supporting high-power devices, and providing 3584Wh of energy and a maximum load power of 2560W.

Visit LiTime RV lithium batteries and choose the ideal battery for your RV.

Tips for Maximizing Efficiency and Prolonging Battery Life

Regardless of the type of fridge you have, there are several things you can do to maximize its efficiency and prolong the life of your RV's battery.

⭐Keep Your Fridge Full⭐

A full fridge is more efficient than an empty one because the food and drinks inside act as insulation, which helps to maintain the desired temperature. Try to keep your fridge as full as possible, even if it means filling it with jugs of water.

⭐Use A Thermometer⭐

Place a thermometer inside your fridge to ensure that it's maintaining the proper temperature. The ideal temperature for a fridge is between 35 and 40 degrees Fahrenheit.

⭐Park in the Shade⭐

When parking your RV, try to park in the shade to keep the interior of your RV cooler. This will help reduce the workload on your fridge and prolong your battery's life.

⭐Use A Solar Panel⭐

Consider installing a solar panel on your RV to help recharge your battery during the day. This can help offset the power used by your fridge and reduce your reliance on your RV's engine to keep your battery charged.

⭐Turn off Unnecessary Appliances⭐

When driving, turn off any unnecessary appliances, such as lights or TVs, to reduce the load on your battery. This will help ensure that your battery has enough power to keep your fridge running.

Conclusion

In conclusion, whether your RV fridge will run off the battery while driving depends on the type of fridge you have and the size of your battery. Absorption fridges will continue to run off propane gas while driving, while compressor fridges will only run off the battery if your RV's engine is running.

To maximize the efficiency of your fridge and prolong the life of your battery, keep your fridge full, use a thermometer, park in the shade, consider using a solar panel, and turn off unnecessary appliances while driving. By following these tips, you can ensure that your fridge stays cold and your battery stays charged throughout your road trip.