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You might be having a problem with your RV battery or just don’t want to replace it. It is expensive and a hassle after all. I’m assuming you have an external power source. So you are wondering if you still need your RV battery if the RV is plugged in?
As a general rule, if you are connected to an external power source, it is not necessary to have a battery. This is true as long as the converter is connected and working correctly. However, you will be without a backup power supply in case of a power outage.
To put it simply, if you have shore power, you won’t need to use your battery power. The modern smart systems on your rig will switch the AC power to still operate the DC systems.
I know, I know, what I just said may not make much sense without knowing about RV electrical systems.
Read about the other resources under the electric and battery series for your RV:
- RV Electric Setup Basics (RV Plugs and Voltages)
- Running an RV Furnace (battery, generator, 110)
- How to Set Up an RV for permanent Use
Electrical Systems in an RV and How it Works
Here’s a breakdown of the electrical systems in an RV to understand the topic better:
Engine Chassis Electrical System
The first electrical system in a drivable RV is not truly in the RV but in the engine of the vehicle. We can get this out of the way first since motorhomes and campervans actually have two different battery systems. In a travel trailer, this system is also separate as part of the tow vehicle.
This is what makes your vehicle work or the automotive system. It controls the vehicle’s dash accessories, lights, and the like. On a travel trailer, it is connected to the trailer in the hitch and runs the brake lights, among other things.
The main purpose of this electrical system is not to power the appliances you will be using inside your RV. It powers your vehicle itself.
This is mainly needed when you are on the road and traveling because, without this, your engine will not start. This also powers the brake lights and other accessories.
AC Shore Power Source
RVs have separate battery (DC) power systems and alternating current (AC) systems. The AC system is similar to the electricity flowing through the wires and outlets in a home.
Shore power is an external source where you can connect to your RV in order to bring AC current inside for the use of your appliances.
Campgrounds usually provide an external 120-volt alternating current (AC) electric source or shore power. You can plug your RV into it.
The power receptacle will have a 30 amp and 50 amp plug (sometimes a 15 amp) to connect your power cord. (The power needs of your RV will determine whether you need 30 amps or 50 amps.)
Caution: You can always step down the amps but never connect to more amps than your RV is designed for.
RVs usually have a long power cord that allows you to plug your vehicle into the source. If your RV does not have long enough one, you can have one installed by a specialist or professional in the field.
DC Battery Power
Most RVs have at least one deep cycle battery which provides 12-volts direct current (DC) to the RV. This is a fully separate system that powers some of the lights and appliances.
This is where you store power, which you can use when you are not connected to any shore power.
Your battery will generally be able to supply power to your outlets through an inverter. I know, it’s a little confusing since the outlet that you charge your phone with actually needs AC power.
I talked earlier about the use of a converter. The converter changes the AC power to DC power to charge the batteries and run some of the DC systems. If you are still not clear read our RV electrical system basics here.
When comparing battery capacity to shore power capacity, the battery has a lower capacity to provide electricity to your RV. The batteries will drain over time and not provide consistent power.
You can also connect two or more batteries in series creating a battery bank. This helps you to have a larger supply of power and a longer connectivity time. Especially if you will not be able to charge your battery whenever it gets drained.
Will Your RV Work Without a Battery?
Your RV needs a minimum of one power source in order to function and supply power to your appliances. If you are already connected to shore power source, you do not need a battery, as long as the converter is working properly.
When you are connected to shore power, this power will go into your RV’s converter, which transforms the 120-volt AC power into the 12-volt DC power. The converter is a critical piece of the two separate RV electrical system. Some of the lights and appliances will run only on DC power and require either the battery or the AC power converted to DC.
Being connected to shore power is more convenient as compared to being connected to a battery. You don’t have to be worried that your power might run out any minute. You don’t also have to minimize your consumption in order to prolong the life of your battery.
However, if there is a power outage (which happens) you will be left without a backup power source. So although you are plugged into shore power, things like your refrigerator will stop working.
What you CAN do and SHOULD do here are different. Yes, your RV or travel trailer will operate when connected to shore power as long as the power supply is consistent. Power outages are common at campgrounds though.
Does the RV Battery Charge when Plugged in?
Most modern RVs have a converter that changes the AC 120 volt power to DC to run the DC system and charge the batteries. However, if the converter is not connected directly to the battery, the battery will not charge when the RV is plugged in.
I can say, that my travel trailer does not charge the battery when plugged in. The converter was not originally wired or has been disconnected. The simple solution is to run a small trickle charger from an outlet to the battery.
The battery is on the front of my travel trailer and a storage area sits just behind that. So I have the trickle charger plugged in inside and the wires running through the storage area to the battery.
An even better solution would be to take your RV to an electrician to diagnose the problem. An electrician could make a more permanent fix to charge the battery while plugged in.
Should You Disconnect Your RV Battery When Plugged in?
Most newer RVs are equipped with smart systems that will only charge the battery until it is fully charged and maintain that charge. In this case, unless the RV is in storage it should be connected while plugged in. If you have an older RV or faulty system the battery could be damaged over time.
Although this being said, it is still important to remember that batteries differ from each other. You have to check if your battery can withstand being plugged into an external source for a long time or not.
When you are connected to shore power and your battery at the same time for a long period of time, overcharging may happen that can damage some older kinds of batteries.
If you have this kind of battery, it is advisable for you to disconnect your battery from your RV once it gets fully charged to avoid it from getting damaged.
With newer batteries, converters and smart systems are now equipped with technology to protect the battery life. These have the ability to stop charging on their own when it’s fully charged.
If you have this kind of battery, you do not have to disconnect it even if you’re already been connected to shore power for a long time. There would less likely to be a problem with overcharging.
If you do not have the newer kind of battery, an option is to purchase a float charger that will allow you to have battery maintenance mode. With this, you can leave your battery connected for a longer time and would only receive the maintenance charge that it needs.
Factors Affecting Your RV’s Battery Life
Although these may vary from every battery, here are the possible factors that may affect your RV’s battery life:
Overcharging – Leaving your RV battery plugged long after it gets fully charged can deplete the battery cells’ electrolyte levels. This can lead to reduced battery life.
- If you have a lead-acid battery, you can add distilled water, not tap water or any other kind of water, whenever your battery’s electrolyte levels get low.
- However, it is important to take note that this will only bring the battery’s electrolyte level back to normal, but not prevent it from reducing its battery life.
Undercharging – Sulfation is a buildup that may happen whenever your batteries are undercharged or not fully charged for a long period of time. This will prevent the chemical-electrical conversion that your battery needs to function, therefore reducing its ability to hold a charge.
- Recharging your battery immediately is the best way to prevent this and when you are storing your battery, you have to make sure that it’s at least 80% charged if not 100%.
Parasitic Loads – As the name implies, these are loads connected to your battery that consumes its power like a parasite most especially when your RV is not in use. This includes small electrical devices like gas detectors and clocks which can lower down your stored power unknowingly and reduce battery life.
- You can equip your RV with battery disconnecting switches to turn these small electrical devices off and prevent them from consuming your stored power when you’re not using your RV.
Change in Temperature – Your battery can lose its voltage capacity over time due to exposure to too much heat or too much cold.
- So either you’re using or storing your RV batteries, make sure that it will not be exposed to too much heat or freeze due to too much cold.
Maintenance of Your Battery
Like the factors that may affect your battery, battery maintenance may also depend on the type of battery that you have.
Lithium batteries for example need less maintenance as compared to others.
It is still advisable for you to look up the specifications of your own battery, but generally, these are the things that you can do to help maintain your battery:
• Maintain your battery electrolyte levels – Frequent battery charging may cause this to decrease so adding distilled water is needed whenever necessary. There is a level marking for you to see if your battery is low on electrolytes and it is also important to remember not to overfill your cells.
• Clean your battery – Cleaning your battery is also important to remove possible corrosion buildup on it. It is important to properly clean and rinse it with water and use a brush for scrubbing whenever necessary.
• Check your battery cables – It is also important to clean your battery cables and check if there are tears anywhere for this may cause you connection problems on your trips or it may even cause a fire.
• Don’t place it near flame – Remember never to bring your battery near a flame for the battery vapors can ignite and cause big trouble.
• Bring your RV for a check-up with a specialist – Having your RV and batteries checked by professionals will always be the best option to maintain and prolong your battery’s life as well as your RV’s.
Final thoughts if Your RV will work witout a Battery
To wrap things up about whether you need to have your battery plugged in whenever you’re already connected to shore power, the simple answer is no, it is not necessary.
Having your batteries connected to your RV whenever you already have shore power is optional, although it may be beneficial to do so when you are on a campground in order for your battery to get charged and ready for your next trip.
Just always remember to check into your batteries in order to avoid possible problems and for them not to be undercharged or overcharged most especially when you do not have a float charger to protect your battery from overcharging.
Always be ready and have routine checks for your RV, to make it simple I’ve created a checklist that you can download from Etsy.
If you need more resources for your RV, I have a whole page of useful tips that you can go back to whenever you have questions. To start, here are some of them:
- How Far Can an RV Go on a Tank of Gas
- Can RV AC Run All Day?
- The Best Length for a Travel Trailer (Size Chart Included)
- What Driving License Do I Need to Drive an RV in the USA?
Hi, I’m Shauna – Welcome to Family Travel Fever. We are a large family, that was bitten by the travel bug! I take the kids by myself because I don’t mind flying or driving solo with my crew to discover the coolest places.
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