RV Electrical

When hooked up to shore power, as many people call it, the RV draws its electricity from the outlet provided. It requires more current than what household outlets can provide which are typically fifteen amps. The standard for a Class A or Fifth Wheel is fifty amps and a Class C (and everything else) usually draws thirty amps.

Does this mean that you can't plug your RV in at home? Yes, it can be plugged into a normal outlet using a cheap adapter that you can buy from any RV store (the prongs on the plug are physically different to the ones at home). The only issue is that you can't run everything that you could with a connection to a dedicated RV power source. Some lights and a TV are okay, the fridge will run just fine but start cranking up the air conditioner and you'll overload the system in seconds. If you want to run with full amenities at home then your local electrician can easily install a higher capacity outlet in your garage or outdoor area.

When not on the road, an RV can make a great spare room or extra sleeping area for when a relative stops by. If you think you might find yourself in the situation of having someone living in there then it might be worth considering that extra outlet.

Once you unplug and leave the comforts of home, you are running on battery power alone. Unlike shore power, the house battery is a finite resource and to be effective it requires monitoring. The battery in your RV is different to the battery in your car and it’s important for the RV owner to understand how the system works.

The most important tool you can own for diagnosing problems and working on electrical systems is a multi-meter. Unless you’re repairing complex electronics, a cheap one works as good as an expensive one. They’re at Amazon or your local hardware store for not a lot of money and it’ll pay for itself the first time you use it.

A regular car battery is designed to maximize the available power to kick out a high amount of current for a brief period to crank the engine. The RV battery, better known as a deep cycle battery, does just the opposite. It’s intended for smaller draws of current over a long period. In a pinch, they are interchangeable and yes they will work but after more than a few days of inappropriate use, they'll both be finished and suitable for nothing more than scrap metal. Use the right battery.

Just to confuse the issue, there are now plenty of hybrid batteries sold by the big chain outlets. They’re just a starting battery with thicker lead plates that can take more punishment. Marketed as combination batteries for RV and marine use, if you use them as you would a true deep cycle battery, you’ll find that they just won’t perform and the life expectancy will be far less than the real deal. The hook for these batteries is the price. They’re cheap and will do the job but if you’re looking for a deep cycle battery and see the letters CCA on the label then just be aware that it may let you let you down.
As stated, the intended use of a deep cycle battery is to trickle out current over the course of the day. If you look at the sticker on one you'll see that unlike starting batteries rated in Cold Cranking Amps (CCA), deep cycle batteries are rated in Amp Hours and that is literally how they are measured. If a battery is rated for one hundred Amp Hours then that means (in a perfect world), that if that battery is fully charged then it can deliver one hundred amps of current for one hour before it dies. That is the point from where it can be broken down: fifty amps for two hours, twenty-five for four and I'm sure you get the picture from there.

A battery is like a glass of water. If you drink half the cup then to have a full cup again, you need to refill it with the same amount that you drank. If your battery is at fifty percent capacity, and then fifty amps need to go back in to in order to recover that original hundred amps. It really is that simple: power in, power out. There are charging losses involved from heat and other factors that are too complex for here but suffice to say, if you use it then you have to replace it. Best practice is not to allow a deep cycle battery to drop below fifty percent before recharging.

As you drive, the alternator in your car is charging both your starting battery and your house battery. The charge rate is usually around the ten-amp mark so a quick calculation tells us that putting fifty amps back in the battery will take about five hours of solid driving, and that’s after your car battery has had its fill so the reality may well be eight hours or more. If you're dry camping then that is not going to happen so in order to charge the battery, other means are necessary and that would either be a generator or solar.