Monday, January 17, 2011

12-Volt Electrical System

The electrical system in your Lazy Daze is a little more complicated than that of your home. Basically there are two major systems in your LD: a 110-volt AC system that is similar to your house and a 12-volt system that provides power when you are not plugged into the electrical grid, either at home or in a campground. The 12-volt system allows you to boondock without utility hookups and enjoy most of the conveniences of home. Check out the 110-volt AC System FAQ for more details on that.

The 12-volt system, as built by the factory, is powered from two different sources. The heart of the system is two Trojan T-105 6-volt batteries wired in series to provide 12 volts of power when not connected to shore power. Trojans are known for their durability and longevity, provided they are properly maintained. When connected to shore power or the generator, the 12-volt system is powered through the converter that is standard on all Lazy Daze motorhomes. On the front of the converter is a 12-volt panel with a number of fuse positions for the various 12-volt circuits in the coach.

As noted in the Battery Maintenance FAQ, it is important to keep your batteries as charged up (full of power) as possible, especially when boondocking. The batteries can be charged in four ways: running the generator, plugging into shore power, running the LD's engine, or optionally with solar panels.
When boondocking, it also pays to be aware of the current draw of lights and appliances, so you can make the available power in the batteries last as long as possible. Some folks have replaced the incandescent and fluorescent bulbs in the fixtures with LED bulbs that draw significantly less power. Many folks install a battery monitoring system, such as the Link-10, LinkPro, XBM or TriMetric that keeps track of battery use. Its computer keeps a running total of every milliamp that goes into or comes out of your battery bank. If you're a frequent boondocker, you might consider adding more batteries for storage of power and more solar panels to feed them.

There should be a matching of battery capacity to power needs.  In general, it is considered bad form to repeatedly draw down the batteries too far.  How much is too far?  Some say 50%.  Some say more, and some say less.  It seems clear that the less you draw down your batteries, the longer they will last.

12-volt appliances or lights fail to operate:
The obvious place to start is to check the fuse. The 12-volt panel uses standard automotive flat-blade fuses of varying amperage, depending on the circuit. You should keep a supply of spare fuses handy.

Caution: If a fuse keeps blowing, do NOT replace with a higher-amperage fuse - find the source of the problem and repair it. Otherwise you may face a hazardous fire situation.

The entire coach 12-volt system is inoperative:
There is a 12 Volt 100 Amp manual reset circuit breaker located typically on the back wall of the battery compartment. There is also a 12 Volt 50 Amp manual reset circuit breaker located inside the coach very close to the enclosed battery "box". The location varies with the floor plan. On the RB, it is under the forward dinette cushion and u have to remove the screws from the plywood cover over the battery box to get to it. Some rigs may even have two of these. The "inside" breaker is a small gray plastic box about 1.5 inches by 1.5 inches by about 3/4 inches with a tiny black reset button. If you lose ALL 12 Volt power, this is the one to look for. On one new rig, a "run-away" ShurFlo 5.7 water pump caused this breaker to trip (50 Amps!!!!!!).
Contributors: Terry Tanner, WxToad
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