[VAC] Re: Why Car & Trailer Battery to Univolt?

["Weimers" <mweimer@xxxxxxxx>]

> > I don't consider that the starting battery should be isolated from the
> > ignition battery in the tow vehicle.
>

Then I replied:

> My system does double duty. First it isolates the trailer from the starter
> battery., and second, it isolates the starter battery from stupid drivers
> who leave their lights on by accident

After I sent this, I realized that you are RIGHT about this. You can not
isolate the ignition from the starter battery like I did. The only reason I
can get away with doing it the way I did is because my car is NOT computer
controlled!!  You would never want to discharge the battery that the
computer is hooked to. The battery that the trailer is hooked to should be
the "extra" battery in the engine compartment. All the wires to the tow
vehicle (starter, ignitions, lights, etc.) should be on the battery that is
isolated from the trailer.

 My original thinking is as old as my car is, I'm afraid!  My system works
for me. If I discharge my accessory battery a whole bunch because I left my
lights on while I was shopping at Wal-Mart, there might still be enough
battery power to run the ignition system and the starter solenoid. The
solenoid will kick in the nice fresh starter battery and the car will start
just fine.  On the other hand, if it is hooked up the correct way that you
proposed, there will not be enough battery power to run the starter motor
since that battery will be discharged. But, not to worry!  The trailer
battery will not be drained at all in this case. All you would have to do is
get out a jumper cable and hook the two positive battery terminals together
and you'll be on your way.

Sorry. I was wrong. I hope I didn't mislead anyone!

MARC WEIMER
Punxsutawney, PA  -  Home of the Groundhog
#15767
1963 Globe Trotter
1971 Globe Trotter
http://users.penn.com/~mweimer