Re: [A/S] EU3000is , Honda

["Jim Dunmyer" <jdunmyer@xxxxxxxxxxx>]

George,
 Anyone who is planning on using his/her battery system for more than a few
minutes' power should have a "battery load tester". These things have a
voltmeter, heavy leads with battery clips, and a switch that brings in a
heavy load resistor. You attach it to your battery, read the voltage, then
hold the switch over to load the battery for 10 seconds. If the voltage sags
very much, your battery might well need replacement.

A friend was out (in his SOB) last w/e, and found that his furnace soon
killed the battery. Yet, he was able to plug in the cord to his tow vehicle
and operate for the next several days w/o problems, and I don't think he
even ran the engine to amount to anything. He dug the battery out of its
nearly inaccessable location in the trailer with the comment, "It ain't
going back in THERE!" Likely as not, that battery is shot, and he only
bought the trailer last Summer.

Once again, the standard converters that are used in RVs are very unkind to
batteries. If you're to depend on the battery for power, you simply must get
a decent charging system on board and you should add some sort of quality
battery monitoring instrumentation in the form of a digital voltmeter. The
little lights that are installed in most RVs are useless for monitoring the
health of your battery. And, unless you do an occassional load test, you
have no idea how good your battery really is.

Here's an interesting chart:

Voltage         State of charge
12.6+                100%
12.5                    90%
12.42                   80%
12.32                    70%
12.20                    60%
12.06                    50%
11.9                        40%
11.75                    30%
11.58                    20%
11.31                    10%
10.5                        0%

Voltage is to be read after the battery has rested for a while, not while
under load. For best battery life, you should avoid drawing the battery
below 50% charge. Note that this is 12.06 volts, only 1/2 volt from fully
charged. When you notice that the lights are dim, you've discharged the
battery nearly 100% and are doing permanent damage to it.

With a good 3-stage charger, you can charge the battery about 80% in just 3
or 4 hours, making operation from your generator practical without having to
run it all the time. Many folks try to charge their batteries by using the
genset to power their standard converters, and a quick check with an ammeter
will show the futility of this approach.

BTW: a good battery load tester should cost well under $100.00, and a decent
voltmeter that can be permanently mounted in your RV is available for less
than $50.00.


<<Jim>>