Re: [VAC] Solar Power

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Don,
 Good points on the capacity numbers and the ability to actually run a
charging deficit for short trips.

I'll slightly disagree with your statement below about 'inability to
bring the battery to full charge with the solar panels'. Actually, mine
will, the charge regulator is set for 13.8 volts, which is high enough.
What solar systems will NOT do (even the large, stationary outfits) is
equalize the cells in the battery by providing a controlled overcharge
for 5 or 6 hours.

It is absolutely necessary to 'top off' the charge in a lead acid
battery on a regular basis, certainly at least every other month. This
is done by charging it at a rate of C/10 -> C/20, where 'C' is the
capacity in AH. That means that our typical Group 27 battery should be
charged at a rate of 5-10 amps for 5 or 6 hours. This causes the cells
to gas and brings all of them to full charge. Make sure to check the
water first!

I have 3 pairs of Group 27 batteries on 3 computer UPSs here 
(see
http://www.oldengine.org/members/jdunmyer/personal/computer/jun08_10.jpg)
and have found that a set of batteries will be shot in about a year if
not equalized regularly. Your UniVolt may equalize the battery OK, in
fact will probably overcharge it slightly if you leave it plugged in all
the time while at home.

All of this stuff can be discussed for long periods (and has been, right
here!), but it's really not all that complicated: Get your usage in
line, do the simple arithmetic, then get a solar panel or 2 and a
controller. Plug in the Univolt every now and then for a day or 2 to
equalize the charge. Keep your battery(s) clean and full of water.
You'll have all the power you need if you follow those simple steps.

Again, YOU probably know all of this, but some newcomers don't. Great
recommendations for additional reading, too!

                                  <<Jim>>