Re: Charging from tow vehicle

On Sun, 9 Mar 2025 16:39:12 -0500,
  sticks <wolverine01@charter.net> wrote:

 On 3/9/2025 9:33 AM, Ted Heise wrote:

On Sat, 8 Mar 2025 19:38:39 -0000 (UTC),
   Ted Heise <theise@panix.com> wrote:

       ...The low power over the 7-pin is pretty unlikely to
  ever get the LI battery up to full, unless it's very close
  before starting a day of towing.

  From this, I take that the fridge draws so much that it
  robs from the LI battery as well as from the Acadia.  My
  impression is that if the LI battery is relatively full at
  the start of a towing day I should just disconnect it while
  towing so it doesn't get drawn down and it's SOC is
  preserved.  The fridge should run okay on only the jiuce
  from the Acadia via the 7-pin.
>
  on the other hand, if the LI is low on charge when I start
  a day of towing, I could consider leaving it connected and
  running the fridge on propane.

 
A couple of additional thoughts I meant to work in.
 
First, I expect the fridge was at its max demand when I tested
yesterday, because I'd just started it up.  Seems the draw
would be less (at least the duty cycle would be lessened) once
the inside has reached temp.

 
 Yeah, I thought that too, and it kind of is confirmation where
 in the Lance docs is says to turn it on a day ahead of time to
 get it cold.  I don't think it's that it uses less power, it
 just runs less.

Ueah, that's what I meant by a lower duty cycle, running less of
the time.  Maybe I misused the term.

Second, it seems possible that once the Acadia's battery has
been fully charged the alternator output might drop and the
trickle charge going out via the 7-pin to the Lance would also
drop.  I figure I can watch this next time we are actually
towing.

 
 Well, it does appear you've got a much better handle on exactly
 what your equipment does, and what the capabilities are.  If
 you choose to improve on them with a DC to DC generator or a
 solar array, you now have a good base of information to go
 with.  Nice job, Ted!

Thanks, sticks!  I appreciate all the feedback as I worked through
this.  I don't have a final plan yet, but feel pretty well up on
what's happening and what my options are.

--
Ted Heise      <theise@panix.com>       West Lafayette, IN, USA