How Long Will a 12-Volt Battery Run a Refrigerator?

Introduction:

When it comes to powering a refrigerator during a power outage, the choice of battery plays a crucial role in determining the backup time. In this article, we will explore the capabilities of a 12-volt battery in running both residential and RV refrigerators. Additionally, we will discuss the impact of battery type, such as deep cycle lithium batteries or lead-acid car batteries, on the backup time.

I. Understanding the Power Requirements:

To determine the backup time of a 12-volt battery for running a refrigerator, it is essential to consider the power requirements. This includes the running power and the starting watts of the refrigerator.

II. Residential Refrigerators:

A. Inverter Capacity and Battery Selection for 110-220V Refrigerators:

Residential refrigerators typically operate at 110-220V and have an initial spike of starting watts. To calculate the inverter capacity, it is important to consider the starting watts, which is usually higher than the regular running power. In this example, assuming the starting watts are 720 watts and the regular running power is 240 watts, the inverter capacity should be at least 1500 watts.

B. Backup Time Calculation for Deep Cycle Lithium Batteries:

If a deep cycle lithium battery is used, the battery’s capacity should be sufficient to meet the power requirements. In this case, using a 12-volt deep cycle lithium battery with a capacity of 200Ah, the backup time can be calculated as follows:
Battery Power (Wh) = Battery Capacity (Ah) x Battery Voltage (V) x Number of Batteries
Backup Time = Battery Power (Wh) / Connected Load (W)
Therefore, with a battery power of 2400 Watts and a connected load of 240 Watts, the backup time is approximately 10 hours.

III. RV Refrigerators:

A. Inverter Capacity and Battery Selection for 12V RV Refrigerators:

RV refrigerators typically operate at 12V and have specific power requirements. Considering a running power of 250W and starting watts of 750W, the inverter capacity should be at least 1500 watts.

B. Backup Time Calculation for Lead-Acid Car Batteries:

In the case of using a lead-acid car battery, the battery’s capacity should be sufficient to meet the power requirements. With a volt amperes of 250 and a 50% depth of discharge (DOD), the backup time can be calculated as follows:
Battery Power = Volt Amperes (VA) x Battery Voltage (V) x Number of Batteries
Backup Time = Battery Power (Wh) / Connected Load (W)
If the lead-acid battery is rated at 200Ah, the backup time can be estimated as approximately 9.6 hours.

IV. Conclusion:

In conclusion, the backup time of a 12-volt battery for running a refrigerator depends on various factors, including the battery type, inverter capacity, and power requirements of the refrigerator. In the case of a 12V 200Ah lithium battery, the backup time is approximately 10 hours, while a 12V 200Ah lead-acid battery provides a backup time of around 9.6 hours. Choosing the right battery type and capacity is crucial for ensuring uninterrupted power supply during an outage.

FAQs:

Can I use a 12-volt battery to run a residential refrigerator during a power outage? Yes, a 12-volt battery can be used, provided it has the appropriate capacity and the inverter can handle the starting watts of the refrigerator.
How does the battery type affect the backup time? The battery type, such as deep cycle lithium batteries or lead-acid car batteries, impacts the backup time due to variations in their capacity and efficiency.
What is the significance of the inverter capacity in running a refrigerator? The inverter capacity should be sufficient to handle the starting watts of the refrigerator, which are higher than the regular running power.
Can I use a 12-volt lead-acid car battery for an RV refrigerator? Yes, a 12-volt lead-acid car battery can be used, provided it has the appropriate capacity to meet the power requirements of the RV refrigerator.
Is it important to consider the initial spike of starting watts when selecting a battery? Yes, considering the starting watts is crucial as it determines the inverter capacity and the battery’s ability to handle the sudden surge in power during startup.