David:

The meter also reads out in watt hours, and a few other things as well. For
anyone interested in the watt hours, it's reading 275 Wh's. over almost 24
hrs at this point. I guess that amp hours is something I understand a little
bit better, as the battery is listed in amp hr capacity. The deep cycle
marine battery I have for example is a 125 amp hour battery. Using 20 amp
hours of that is something that I can relate to. I don't know how many watt
hours the 125 amp hour battery contains, and I guess that depends on voltage
according to your description. Knowing that my 125 amp hour battery is
capable of delivering about 65 or so AH's,(50% battery depletion)  I know I
can run my fridge for about three days before the battery needs charged, and
that's the most useful information for me. I realize this is a very
simplistic approach, and other variables apply, but I think it's good enough
for general calculations. Do you agree?  Fridge is now at 26�, so guess I
need to change the settings. Amazing little unit I must say...

Troy

From: "David Beierl" <dbeierl@attglobal.net>
To: "Troy" <colorworks@GCI.NET>
Cc: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, July 07, 2013 1:14 PM
Subject: Re: Vitrifrigo temp data

> At 04:37 PM 7/7/2013, Troy wrote:
>>I'm not sure if anyone else has plotted the electrical usage, but on my
>>"watts up" meter it appears I've used almost 20 amp hours in 21 hrs, so
>>about one amp per hr, which I thought was actually pretty amazing. This is
>>the first
>
> Just being pedantic here...that's one *amp-hour *per hour, or an average
> of one amp consumption.  Amperes is a rate of charge transfer (coulombs
> per second), ampere hours is an amount of charge (one amp hour would be
> 3600 coulombs, or the amount of charge in about 240 average-size lightning
> bolts (or ten really humongous ones)).
>
> To get the most accurate picture of consumption you have to go one step
> farther and look at watt-hours, if your meter will do that.  An amp-hour
> at ten volts has ten times the energy of an amp-hour at one volt;
> watt-hours takes voltage into account and gives energy directly.
>
> Yours,
> David