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Is it Bad to Leave Your RV Plugged in All the Time

For many newcomers to the RV lifestyle, a flat battery is a scary perspective.

Therefore, many opt for leaving their RV batteries charging for weeks on end.

But is it bad to leave your RV plugged in all the time?

What are you risking with this practice?

In reality, overcharging can be just as damaging to your deep-cycle batteries as letting them drain out completely. Doing so will progressively shorten your RV battery capacity, as it damages their internal chemistry.

rv plugged in to shore power

Why Would I Even Want to Leave my RV Plugged In

People who leave their RV plugged in all the time usually do it due to one of two reasons:

The first reason is forgetfulness.

When many vacationers return home for the winter, they often leave their RVs parked at home for a few months.

Once anchored and hooked to shore power, it is very easy to leave it there until it’s time to take off again, maybe three to six months later.

If this is done without any safeguard or protection for your RV’s batteries, it can lead to trouble.

The second reason may be to prevent cold damage. In icy regions, the weather could damage some electrical systems, pipes, and appliances inside the RV.

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To prevent this, some owners leave the RV plugged while “trickle charging.”

Then, they make sure to enter the RV at regular intervals to turn on the heating, which protects the internal system from frostbite.

Depending on the frequency, some owners may also turn on a few lights or just spending a few hours watching TV inside the RV to prevent overcharging.

What Can Happen if I leave my RV Plugged in Too Long

The main risk of leaving your RV plugged for too long is that you may damage your batteries due to overcharging.

This progressively depletes the electrolyte levels in your battery cells, shortening their total capacity.

Granted, this risk is not equal for all RVs or battery types.

The most significant risk is faced by:

  • RVs with use acid-lead batteries rather than Lithium-ion ones
  • RVs that are not being used or turned on for several days, despite charging
  • RVs that are not plugged into a converter or electrical management system

The easiest way to prevent overcharging your RV batteries is to ensure you are constantly consuming some of this energy.

Ideally, the batteries should always remain at 97% to 99% charge throughout the offseason.

Often, the best way to do this is by activating the heating and by leaving the fridge or other parasitic loads (such as clocks or gas detectors) consuming a steady trickle of energy.

If you choose this route, you will also need to adjust your maintenance schedule.

Prolonged use produces wear and tear.

You will need to check the clocks, maintain the thermostat, and clean the fridge more often.

Do Converters Protect Batteries When Plugged in for Long Periods

One of the most effective ways to prevent overcharging and protect your RV batteries when plugged for long periods is to install a modern converter or electrical management system.

In this way, you can keep the energy coming into your RV, which will prevent undercharging.

PowerMax PM3-48-18 PM3 Series 48V Charger 20 Amp Power Converter with Quite Fan Cooling and Built-in 3 Stage charging for Trailer Camper RVs

Overcharging and undercharging

As we have seen before, overcharging can permanently damage your battery life.

On the other hand, undercharging refers to regularly letting your batteries drop below 80% or 70% of their total capacity.

This creates sulfation, or the accumulation of sulfur, around the batteries.

This makes batteries less efficient when converting electricity, and it renders them unable to hold a charge.

Frequent undercharging can cause your batteries to start “leaking energy.”

When combined with the hidden consumption of your heating systems, sensors, and alarms, you may be looking at a completely flat battery after a few months of no charge and no use.  

Maintaining optimal voltage with a smart charging system

To protect your batteries, you can use a “smart charging system.”

This is also known as a “three-stage converter.”

These converters are very similar to surge protectors, and they are plugged into the RV’s main cable on one side and to shore power on the other side.

Their primary role is to detect the charge percentage on your battery at any time and to adjust the energy uptake accordingly.

These smart converters usually offer three modes:

  • A bulk mode, which provides the fastest charge until you reach 90% of your battery capacity
  • An absorption mode, which slows energy uptake significantly until it reaches 99%
  • A float mode, which provides an intermittent trickle of energy which prevents it from running flat

A well-installed smart charging system can simultaneously prevent the damage caused by overcharging and by undercharging.

Can I Unplug my RV Too Soon

When it’s time to charge your RV, it is crucial to ensure you bring the charge solidly above 90%.

If you unplug your RV too soon, you may find yourself going below 80% in a matter of days. In turn, this will put you into the undercharging territory and begin the process of sulfation.

Do remember that sulfation is progressive.

If you accidentally unplug your RV too soon and drop into the mid-70s for a couple of days, you may not experience any significant damage to your battery life.

On the other hand, if it stays below 80% for two weeks or continuously dropping below this level, you will see damage accumulate quickly.

Conclusion

When it’s time to park your RV for the winter, many owners wonder, “is it bad to leave your RV plugged in all the time?”

Adding energy to your RV battery without consuming any of it can lead to overcharging, which will eventually damage your battery life.

However, you can prevent this by keeping the heating on or leaving the fridge plugged in throughout the winter.

An electrical management system or “smart converter” can help you better manage energy consumption.

This will change the speed at which your battery charges but still compensate for the hidden “energy vampires” in your RV.

Investing in a smart converter will pay itself back by giving you better, healthier batteries!