Page 4 - Summer 2020 Travelore 50
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             Page 4 - DRVC Travelore
         Electricity in My RV:
A Concise Guide to RV Batteries
Yes, it is true; the sources of electricity for the living space in your RV can confuse the novice. For some, differentiat- ing between AC and DC just makes for more confusion. With this in mind, let’s take a simplified view of informa- tion that may be helpful in understanding the mystery of “the electricity in my RV.”
First, there are two types of ways electricity is used in today’s RV, whether a pull-behind or motorhome: AC (alternating current) and DC (direct current). AC is like that which is in a typical American home where it is sup- plied by an electrical utility. This is because generating and transporting an AC current across long distances is rela- tively easy. Alternating current is an electric current that periodically reverses its direction. Others may describe it as changing polarity over time. Basically, AC is the oppo- site of direct current (DC) which only flows in a single direction and will not change sporadically. But, let’s not get too technical. The graphic (below) is a simplified look at the difference in the way electricity flows.
alone generator when it is running. This is particularly useful for mobile situations like RVing.
Living on the Grid
When plugged into “shore power” at a campground ped- estal, the AC is converted to DC so the 12-volt lights in the unit work. In addition, if you have a propane furnace, water heater, or refrigerator, the 12-volt system is used to power them. Of course, if you have overhead fans, they operate on 12-volt DC, too. While all of that energy is being converted for use, it is also charging whatever bat- teries you may have onboard. The batteries are where DC power is stored so it can be used when untethered from the power grid.
At the same time power is being converted to DC, the RVs system is wired in such a way that AC power (measured in volts and amps) is passed through to the appliances and devices that need it.
If a someone asks why the air conditioner shut off while they were drying their hair and the coffee was being made yet the lights continue to work, just tell them that too much AC current was in demand resulting in an over- loaded circut. The lights still work because they are using DC, that different type of electricity that seldom creates a problem.
And all of this stuff brings us to a discussion of batter- ies. Just keep in mind that the batteries are where the DC electricity is stored. Once stored, it can be used to directly power the direct current circuits and also invert electrical energy to alternating current for temporary use.
Batteries: Take Your Pick, Pay the Price
If you are always plugging into shore power at a camp- ground, it is likely you are only dependent on battery-sup- plied power while on the road. If that is your situation, you primary concern is with proper maintenance and avoid- ance of overcharging.
But, when you are dry camping, you rely heavily on the ability of the batteries to deliver a steady supply of 12-volt power. After all, some of that power is being inverted to supply energy to the AC appliances.
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  Direct Current
Alternating Current
The nice thing about DC is that it is extremely portable and relatively easy to generate and store. AC is not. Because of it’s characteristics, DC is preferred for pro- viding the basic lighting structure throughout your RV. Because of the greater capability associated with AC, it is used for things like the microwave, air conditioners, and things you plug into the wall (hair dryers and table lamps). In all-electric units, AC also powers residential-type refrig- erators from the power stored in the batteries.
Another nice thing about electricity is that the operating characteristic can be converted from alternating to direct and inverted from direct to alternating current. While most pull-behind RVs only have a converter and battery, typical motorhomes have inverters connected to a battery bank (for storage) that receive energy from the stand-

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