Re: [A/S] Electrical Independence

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Bob,
 The biggest problem with charging from the tow vehicle is the voltage
drop in the wiring. Jan & Bill Moeller claim in their book that #4
welding cable (and appropiate connectors, such as those for electric
forklift batteries) is required to do an adequate job. The little bit of
experimentation that I've done tends to verify that, I've measured a
charge rate of <5 amps. If your 105AH battery is at 50% charge, you're
looking at 10 hours or more to bring it back. And, your truck is going
to use a significant amount of fuel during that time.

When you price out the quantity of #4 welding cable and the connector
plugs, you might have a change of heart on the solar system. :-(

The great part about a solar installation is that it doesn't have to be
done all at once, you can piecemeal the system. Get one panel today and
add more at later dates. If you don't want the expense and trouble of
replacing the charge controller, buy the one you'll eventually need
right off the bat. When I bought my first panel, I bought a 6-amp
controller for about $20.00. Adding the second panel made that
controller too small, so I had to buy a larger one for about $35.00.

DO NOT buy one battery and figure on adding another at a later date,
paralled batteries should be as near-identical as possible, and that
means age in addition to capacity, manufacturer, etc. Either figure on
running one battery until it's used up, then upgrading, or buy the
entire bank at the same time.

You really, really should have both Barre's and Moeller's books on RV
electrical systems.

                                     <<Jim>>