Battery chargers are great for keeping your RV’s electrical system up and running. They save you from having to purchase additional power when you run out of juice, and many also charge your batteries as well.
But what if you’re hooked up to shore power? Will the battery charger still work when plugged into the shore power port?
The answer is yes, but this could have an impact on how fast the battery charges.
Table of Contents
Do RV Batteries Charge When Plugged into Shore Power?
Many camping trips require an RV to be plugged into shore power rather than using a generator. After a few hours of charging, the battery will be fully charged and can then be left connected onshore as a non-energized source for portable power.
At some point during this process, the battery will accumulate sulfate buildup that lowers the voltage output and increases gas consumption until it will no longer hold a charge.
This happens to most batteries on shore power in one way or another, but that doesn’t mean you need to junk them. With the right maintenance and care, soon those old RV batteries will be ready for their next trip!
So What Happens When we Plug an RV Battery to a Shore Power?
When plugged into shore power, most RV batteries will charge and discharge. Others continue to charge when their outlet is connected directly to a 120 volt source such as a wall outlet.
The reason for this is the 50/60 cycle.
The shore power voltages are sometimes higher than most RV’s electrical systems can handle and would over-stress the system with high amperage loads, causing damage to electronic components as well as potentially leaving your battery inoperable due to a fire or explosion of extreme heat.
In order stop this from happening, they lower the voltage output to 29 volts instead of 45–48 volts which then they are able to charge.
Most of the time, this will keep stalling them safely in the charging zone which is what you want and it allows for a full-ride without worrying about overcharging due to high voltages.
There are exceptions though with certain models so please take care when doing research on your particular vehicle and system(s).
Understanding the RV Electrical System
The electrical system in an RV’s consists of a number of components, including the wiring and brake power. There are three main types of voltage regulators:
-CB, CB Auxiliary RV Battery, and CB Wired In House Battery. Voltage regulators provide voltage to the RV circuitry and batteries.
They also remove Electrons from a battery causing increased self-discharge of it’s cells, which result in reduced life expectancy on lead-acid batteries (negating one reason for their short life).
All regulators have an input that is the same electrical current as its output so if you move away or connect another generator with slightly lower then what your regulator requires you can make a regulator malfunction.
Without one you can run your system at full power and drain its batteries or put out a great deal of heat under the hood due to an overheating battery that is being charged via shore power, causing damage….then again if you don’t know what electrical voltages are in your plug (using incorrect ones) this could cause problems as well.
Not all have circuit breakers but most do so make sure yours does .
A few things to do before installing or disconnecting a regulator are: change the battery levels, keep your batteries in good shape (free of corrosion and gas also) seal all vent & access holes on the unit(s).
Since you can easily overcharge/over-discharge most regulators I would advise connecting both if possible so that least one has time to cool down.
Owners’ manuals will indicate what voltage limit each type is set for but when installing your regulator be sure to choose a lower voltage setting than what you want. Wait until all regulator connections are made ,then set the circuit breaker (shut Off) on both isolators.
Now plug in any shore power first, start and run generators instead of running just one or two at once so that they can charge before going into light use (make sure each generator has good reserve Batteries).
Disconnect one RV voltmeter after about 20 minutes (it will show “normal”) and run your generator until it’s down to 110% or so (make sure you are in the campsite and locked if this is not safe).
Now hook up shore power again since it might be 5/10 cents cheaper then camp propane. After about 15-20 mins check flow on RV meter for both units,(generator stopped prior full charged)unplug one isolator, turn generator on and let it charge until RV meter shows full.
If unable to finish 100% then repeat the process with the second unit but replace when in state of being fully charged (should only have 1-1/2 gallon leftover)
12V DC Power
Solar power is a clean and renewable source of energy. Being able to harness Mother Nature’s generous gift has many advantages, such as making electricity available during the night when there are no other sources.
When exposed to direct sunlight, a solar cell converts photons into electrons through photovoltaic (PV) cells.
Most PV cells produce enough energy, even if they’re not in pristine conditions, but some need special types of cells called concentrating PV cells.
Instead of just producing energy as soon if not directly in the path, these PV cells are used to extract more electricity from sunlight and boom with “concentrating solar power” or CSP
12 volt DC into 120/240 volts AC (uses same voltage) can be achieved using a Syncrowave converter . Full 3 phase balanced DC designed for multiple machine operation on load center.
120V AC Power on RV
The AC power wires in your typical RV are likely different from a standard home. They may be thicker, have connectors installed, or even be taped for safety reasons.
When wiring an R V before buying one, it is important to determine the proper AC wire size and connector type in order to avoid expensive mistakes later on.
First, check the batteries: if your RV remote/batteries are not dual voltage as-is ( 12V DC and 120/240 V AC) then you will need to purchase dual voltage wire.
The proper connectors are either main (both male or double female, although now they are all connectors since most manufacturers standardize on same style), GFCI solid copper or ground bus bar depending on the voltages present in your particular wiring system.
It is common for RVs with a design that allows only one device at a time to be plugged into the 120V outlet, to use an adaptor with three prongs (one on each side of the line cord), but this is unnecessary.
When you live in a state that requires compliance wiring, using a GFCI pull cord will allow your unit to automatically detect if electricity is present and shut down should it fail at any point during its operation/when left without service for some period of time.
When used properly it is a great option for the safe operation of any electrical services provided to your RV.
Depending on your specific application, inexpensive transformers or appliances may have an input voltage that does not match with 120V common household outlets. For example, some gas grill styles are wired for 13 V DC and require a #12 style plug adapter.
How is the RV Battery Charged on Shore Power?
As shore power is used to charge the RV batteries, a cable connected to the various AC jacks are plugged into.
Recently many RVers have been opting for dedicated solar panels and inverters(power transformers) from renewable sources such as wind, water or land to generate AC rather than rely on DC that is often supplied by a battery bank.
One of the key benefits of going this route is when using shore power, no conversion of the DC coming in from the generator will occur.
Additionally, when there is sufficient power being used onboard an RV to produce electricity that can be practical, useful or allows a comfortable minimum required use of resources during dockside operation using the shore power supply and when adequate usage outside (LPG for example) still exists with reasonable affordability compared to other means (like purchasing additional machines powered by generators).
It makes more financial sense than loading up with solar or other “green power”. To address the issue of insufficient current being available from shore power , a low voltage device called an isolator is used to deliver and weight load less than 200 watts in conjunction with a constant amount of capacity that can be withdrawn for use onboard based on usage(connected) .
There are several options ranging from simple ones like multi-plug version, up to one purpose-specific adapter. You may have seen them around on docks as they are sometimes used to add a 12 V socket directly into the DC power panel.
How is Main AC Load Power Supplied?
Power systems that supply shore power, either of those with batteries or generators might do this through
1) attaching several series-connected lead-acid twelve-volt battery strings (B1-s), 2) using one -or more- marine diesel engines(D2’s),
3) by connecting the larger output from a generator directly to the shore power inlet(god help you if there is no regulator),
4) by using 3 parallel connections of heavy gauge 12 volt cables (call them A2-a, A2-b, and C1.
5) or with battery banks supplying current through circuitry as described above called an isolator as described below where one string supplies various loads on board based on usage amounts depending on “load control” and “applicable load control mode ?”.
In this case arguably, the most efficient mechanism is #1 but those are not always viable options.
Other Ways to Charge Your RV Batteries
There are many ways you can start and maintain your vehicle while camping. One way is to use the 12v hookup to a generator. The RV inverter will charge the batteries on your RV, as well as run power tools or any other device that needs electricity. Another alternative would be solar power.
Some models only come with a small battery, that kind of limits the size of your rig.
That’s where solar power comes in handy; instead of relying on cable and cords to run appliances or even charge/run tools for camping, you can just rely on nature instead.
You could also invest in an extra-large UPS system like Goal Zero Solar (I have their Poco Panel), which will propel your RV into the world by moving off-grid electricity to wherever you are.
Many people simply store power in their vehicle batteries and opt for solar-powered LED lights, radio, iPod or anything else they like as long as it uses a small amount of electricity and is relatively easy on the wallet! You can also use Solar Panels when Cooking on your RV.
As you can see, there is no right or wrong way to charge your vehicle’s electrical system on the road; everyone has his/her own set of priorities and options based on where they stay, what their needs are and how much they budget for that month while hiring a campervan in Australia.
How Much Does a Wall/tank-Cable/inverter-Discharger Cost to Use?
Most popular brands of RV inverters and chargers expect you to purchase the associated charging accessories (wall or tank cord, mounted inverter plug or outlet) along with their small charge controller. That’s why everyone should really realize that none of these devices are particularly cheap when compared with an onsite generator.
In fact, nowhere is the issue more apparent than with shore power.
Many dealers will charge several hundred dollars just to hook up their RV for a small electrical load (such as one or two standard appliances) and quite often this does not include the required cord(s), outlet assembly(s), extension cords, distribution blocks, etc.
In many cases, you can still get away without an inverter/charger if you’re willing to do it the old-fashioned way and use a wall or tank-connector cord to hook up your main electrical appliances.
This approach can also serve as the least expensive alternative while you’re still getting into shape in terms of making careful battery bank choices on-site, setting up more efficient lighting/heating controls, etc.
Although performing this task with an inverter connection might compromise its value later down the road if better solutions were chosen early on . Believe it or not, but the reason is simple enough:
The vast majority of restaurants and campgrounds have a “generator connection” that sells shore power back into the grid.
This arrangement allows them to avoid having to waste their money on purchasing pricey RV-powered electrical loads.. As such there typically is no need for their landowners/managers to buy stand-alone inverter chargers in order to use this free generator power with R Vs.
Generally this is different in towns and cities with power supplied via a nearby smart grid system, such as those that operate along the East Coast of about America or even more notably with European countries like France .
(It would be worth mentioning here that there are seldom economical choices available for connecting your RV to shore power from an existing model of transportation when traveling elsewhere.) In most cases, you need to know ahead of time (“plan” if you wish) and when you get on location.. No electricity is available until after the generator has already been turned ON.
RV Batteries: How Do They Work?
A process called the charge-discharge cycle occurs when a battery is connected to an external power source, the chemicals within it are made to receive electrons from the power source so they can be reactivated and thus provide usable electricity. This process creates two different states of chemical reactions: discharge and charge.
As electrons from the external power source come in contact with chemical components of batteries and produce current, this state is known as ‘discharge’. During discharge, chemistries in batteries transfer electrons to external sources.
This process is known as reaction and proves useful for loaning power over long periods of time. When being used by applying a load that requires additional energy after charge the chemical components are created once again reactivate thus ‘charging’. On average, it takes about five hours for a battery to discharge completely and be ready for a recharge.
If you own an RV, then you know that charging your battery can be a real pain. Not only do you have to worry about finding a reliable power source, but also the cable to hook up your battery.
This can be especially annoying if you are on the road and need to plug in your RV for a quick charge. Fortunately, there is a solution for this problem; it’s called an electric converter or inverter and it allows you to use shore power as an alternative energy source.
These converters can be used with any kind of electrical device and they allow the owner to use their vehicle as an energy generator while being able to use shore power as their primary energy source.
I`m a current Law Enforcement Officer working within the Counterterrorism Bureau in New York State. I have been Camping for over 20 years. My styles of camping include tent, car, truck, van, and RV travel trailer. I have a YouTube channel where I teach all types of camping with an entertaining method: https://youtube.com/@TheSmallsRVAdventures