Today I was able to fire up my 3 battery system for the first time. A
dedicated 125 amp hour deep cycle was added for the Vitrifrigo fridge
only. With the Zetec it fits easily in the engine compartment and is a
foot from the alternator. I used short #6 wires with a Surepower 1314
between the alternator and the battery, and ran #6 between the neg post
and the engine block.

As part of this setup I added an amp meter for the fridge battery so I
could see how fast it was charging and then know how long I needed to
run the engine to get another night of camping. I was surprised to see
the meter reading over 60 amps going into the battery when I first
started the engine even though the battery was fairly full. This quickly
tapered down over a few minutes to a steady 25 amps. I wonder if maybe I
have too much charging?

I have not been able to pin down the capacity of this Ford alternator. I
have seen it listed as 105 amp, 115 amp, and 130 amp. I don't care much
either way as 105 would be plenty but it would be good to know. I am
measuring 14.5+ volts at the alternator which I believe is pretty common
with modern vehicles but I wonder how good it will be for the battery
long term.  I could slow down the charging rate by switching to longer
and thinner battery cables but this would not drop the voltage much
after the battery was full. That seems too high for a "float charge" but
I don't know how it will be in practice. Anybody know? Suggestions?

Mark