Re: [A/S] Electrical Independence

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Bob,
 Please go back and re-read what I said:

You most definitely CAN charge batteries from the vehicle's alternator.
You CAN'T do it at a decent rate through the #10 wire that's typically
used for hookup, you need to have very heavy cable. If you're unfamiliar
with #4 welding cable, it's a bit over 1/2" OD and the wire itself is
about 3/8" diameter. It sells for between $.50 and $1.00 per foot, and
you need about 75 feet (2 conductors), plus a connector that will run
you maybe $25.00.

As I said, the problem is voltage drop across that #10 wire. The
vehicle's alternator regulator sees the vehicle's battery voltage and
cuts back on the charge rate, so little goes to the trailer. IF the
vehicle's battery was disconnected AND IF the regulator had a connection
directly to the trailer battery to sense the voltage, THEN YES you could
successfully charge it like you want to.

You're envisioning operating on your batteries for a couple of days
until they get "low", then plugging in your umbilical cord and running
the truck's engine for a couple hours to recharge them. From my own
measurements, you'll remove about 60 AH from the batteries over those
couple of days and will return maybe 10 AH or so in a couple of hours.
Look at those numbers and tell me what you think is going to happen.

                                   <<Jim>>