In the world of recreational vehicle (RV) ownership, understanding the ins and outs of proper battery maintenance is crucial. One common question that often arises among RV enthusiasts is whether they should disconnect their RV battery when the vehicle is plugged in.

In this article, we will delve into the pros and cons of disconnecting an RV battery while it is plugged in, providing you with the necessary insights to make an informed decision.

Is it Harmful to Keep Your RV Continuously Plugged in?

In general, the answer is no, especially with modern smart chargers now being standard in most RVs.

Most RVs manufactured in the last decade, whether a travel trailer, fifth wheel, or motorhome, include an integrated converter. This component not only manages power distribution but also converts the Alternating Current (AC) from shore power or a generator into the essential 12V Direct Current (DC) for charging the batteries. Additionally, it actively oversees and regulates the power supplied to the batteries, effectively protecting them from overcharging—a potential threat that could significantly reduce battery lifespan.

To confirm if your RV includes a built-in converter, ideally with a float mode, consult the provided manual or look up the model number for your power distribution panel. If your RV lacks this feature, we can explore alternative methods to ensure your batteries remain charged without overcharging.

For short periods of time (say a month or less), generally, it's acceptable to leave the RV plugged in. However, for long-term storage, especially if your RV has an old or inefficient converter/charger that could lead to overcharging, it may be necessary to disconnect the RV battery to prevent damage. If you store your RV for an extended period, particularly in very cold temperatures, consider completely disconnecting the house batteries and possibly storing them in a warmer location for the winter.

Pros of Disconnecting the RV Battery When Plugged In

1. Extending Battery Lifespan

By disconnecting the RV battery when the vehicle is plugged into shore power, you can prevent overcharging. Overcharging can lead to the deterioration of the battery's lifespan and performance. Thus, disconnecting the battery can help to preserve its longevity.

2. Minimizing Parasitic Loads

When the RV is plugged in, some onboard systems and devices continue to draw a small amount of power from the battery, even though the RV is receiving power from an electrical hookup. By disconnecting the battery, you can eliminate these parasitic loads, ensuring that the battery remains fully charged and ready for use when needed.

Cons of Disconnecting the RV Battery When Plugged In

1. Loss of Auxiliary Power

When the RV battery is disconnected, some auxiliary systems, such as interior lights, carbon monoxide detectors, and propane leak detectors, may lose their power source. This can be inconvenient, especially if you need to use these systems while the RV is plugged in.

2. Limited Battery Maintenance Benefits

Modern RV charging systems are designed to prevent overcharging, making the practice of disconnecting the battery less critical than it was in the past. Therefore, the benefits of disconnecting the battery to extend its lifespan may be less significant with newer RV models and charging systems.

Does the RV Battery Charge While Connected to Shore Power?

Yes, but there are a couple of conditions to consider.

First, check if the battery disconnect switch (typically located near the battery in a compartment or nearby) is set to "off." If it's off, the batteries won't charge until you turn the disconnect switch on. Surprisingly, many RVs are brought into dealerships due to this simple oversight. Often, new RV owners are unaware of the in-line disconnect that needs to be activated.

Next, ensure that your RV is receiving sufficient shore power to meet all power requirements and still have leftover capacity to charge the batteries. For example, if a small 1500 Watt generator is running your RV, and heavy power draw appliances like air conditioning and a hairdryer are simultaneously in use, there might not be enough power left over for the converter to charge the batteries.

Fortunately, modern converters are automatic and seamlessly redistribute power to the batteries when there's a break in power draw, requiring no manual effort on your part.

Can an RV Converter Function without a Battery?

This topic is heavily debated online. The simplest way to find out is to plug your RV into shore power, switch on some lights, water pumps, and other twelve-volt systems, and then turn off the previously mentioned battery disconnect switch.

You'll likely notice that nearly everything continues to function correctly. So, no, for the most part, you don't need a battery installed to operate most of your 12V systems.

However, there's a caveat to consider: devices with high 12V current demands, such as slide-outs, might not function without a battery. This is because some motors require more current than a typical power converter can deliver at once. In contrast, the battery is designed to output power in larger doses.

While many RV slide-outs can operate without a battery, if yours cannot, this information is typically detailed in the documentation accompanying your rig or may be indicated by a sticker near the slide-out operation switch.

Proper Use of an RV Battery Disconnect Switch

Alternatively known as: What is this component, and when should I use it?

An RV battery disconnect switch is a crucial feature for any vehicle with a house battery. A single action (often a twist) allows you to swiftly and easily disconnect the main RV circuit from the battery, safeguarding not only the battery itself but also other electrical components of your RV.

Usually located near the battery in its compartment or in a nearby maintenance bay, this switch is often overlooked or even forgotten, hidden behind various items inside a storage bay.

Batteries tend to discharge slowly over time, even when the appliances they're connected to are turned off. Even in the off position, electrical appliances draw small amounts of energy passively in anticipation of startup. Wiring itself also gradually drains power. This type of energy loss leeches at least some charge from your battery and can ultimately lead to a dead battery precisely when it's least expected or needed.

When to Utilize an RV Battery Disconnect

Understanding the appropriate times to use an RV battery disconnect is essential for all RV owners. When dealing with electronics, it's crucial to take proper safety measures to avoid causing damage or risking injury.

Engaging in Electrical or Appliance Maintenance

Whenever you undertake maintenance in your RV, whether it's replacing a light fixture or servicing the water pump, it's important to pull the fuse for the circuit and consider using the battery disconnect. Not only does this action protect you in the event of an electrical mishap, but it can also help prevent costly issues in the long run. This simple precautionary step is vital for the safe and efficient maintenance of your RV.

Storing Your RV without Shore Power

If your RV will be unused for more than a week or two and lacks the option to connect to shore power (even a standard 15A household circuit is sufficient to maintain the batteries), it's important to disconnect the batteries. Doing so minimizes current loss caused by excess wire runs and appliance trickle.

Using a 7-Pin Receptacle on Your Tow Vehicle

If your RV possesses a 7-pin connection to your tow vehicle, one of the pins provides charging power for your RV house battery. While this capability helps recharge your house batteries during trips, it can also lead to issues.

Leaving your RV plugged into your tow vehicle for an extended period (hours) without the tow vehicle running can result in draining the vehicle battery to charge the RV batteries.

Certain vehicles automatically shut off the power to that pin when the ignition isn't on, whereas older models often lack that function.

What to Do If Your RV Doesn't Have a Built-in Float Charger?

If your RV doesn't come with a built-in float charger, you can consider using an external battery charger or a separate float charger like MPPT solar charge controller and DC-DC charger. External battery chargers can be connected to your RV's battery when it's not in use. A float charger, also known as a battery maintainer, is designed to keep a battery at its fully charged level without overcharging, making it an excellent choice for maintaining RV batteries during periods of inactivity.

When choosing an external charger or float charger, ensure that it is compatible with your RV's battery type (e.g., lead-acid, gel, AGM) and that it provides the appropriate charging voltage and current. Additionally, verify that the charger has features such as automatic voltage regulation and overcharge protection to ensure the safety and longevity of your RV's battery.

Related reading: Why is My RV Battery Dead and How to Fix?

Conclusion

In conclusion, for RV owners, the dilemma of whether to keep batteries connected while plugged into shore power used to be a significant concern due to the limitations of older technologies. However, advancements in RV battery technology have made this decision much easier.

LiTime's deep cycle lithium batteries are built with low self-discharge rates, ensuring minimal power bleed when left connected, simplifying maintenance and reducing hassle. This advantage becomes especially apparent when returning from extended periods away from your RV.

Explore LiTime's range of modern 12V deep cycle batteries and solutions today to enjoy the full convenience of RV ownership without compromising on battery quality!