Last month, we talked about the types of batteries used in RVs. Now, we focus on getting the most out of them. Some terms should first be explained: The three most basic units in electricity are voltage, current, and resistance. Voltage is measured in volts, current is measured in amps, and resistance is measured in ohms. A neat analogy to help understand these terms is a system of plumbing pipes. The voltage is equivalent to the water pressure (potential), the current is equivalent to the flow rate (performance), and the resistance is like the pipe size (results), or how much water leaves the end of the pipe. Now comes that moment when the math you learned in your eighth grade algebra class is finally of some use. Twelve volts (potential) at 4.583 amps (performance) will light a 55-watt bulb (result) for one hour, or 12 times 4.58 equals 54.996. Typically, a 55-watt light is one headlamp on a motor home, and the battery supplying the amps is being recharged by the engine-driven alternator.
An RV’s house batteries, on the other hand, are usually charged by an AC/DC electrical source, like your generator, or when you plug in at the RV park. There are three basic types of chargers available to the RVer:
• The auto chargers you get at Autozone, Sears, etc. These chargers are meant for emergency charging. They are constant potential (13 to 14 volts), constant performance (two to six amps) chargers. Leaving them connected to batteries for long periods will cause damage.
• Installed RV converter powered chargers. These chargers are the best bet for long battery life. They are “taper chargers” with modified potential (13 to 15 volts initial charge, dropping to 12.5 volts near the end of charging). And they have modified performance (20 to 30 amps initial rate, dropping to one amp near the end of charging).
• Float chargers. Some of the higher quality (read expensive) converters have a built-in float charge. This requires the RV to always be plugged in and the converter operating. That’s 60 to 70 watts per hour on your electrical bill. Another type of float charger is called Battery Tender. It costs about $50 at your auto parts store. This float charger comes with a harness that connects directly to your battery, with a quick disconnect to the charger. The float chargers use about 12 watts per hour, and will not over-charge your batteries.
Now that you’re all amped up, get out there and Enjoy the RV life.
Final Touch Coach Works is located at 28532 Livingston Avenue in Valencia. For more information, please call 661-775-8375 and visit www.finaltouch-usa.com .