Oh, no - no saving face here by saying I meant one thing when I wrote
another. I just messed up the arithmetic.
--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR

On 9/5/2009 11:54 AM Dave Mcneely wrote:

> 168 x 0.2 equals 33.6  .  168 /0.2 equals 840 .
>
> Do you mean amp-hours per day, or amps per hour per day (which is what
> you wrote)?
>
> Just making sure.
>
>
> On Sat, Sep 5, 2009 at 1:13 PM , Karl wrote:
>
>> I calculate that usage at 33.6 a/h per day. 24 x 7 = 168 , divide by
>> .2
>> = 33.6.
>>
>> Rocket J Squirrel wrote:
>>> Hi Malcolm.
>>>
>>> A 24-hour run of your refrigerator, if it draws 7A, and has a duty
>>> cycle
>>> of 2/10 (two minutes out of ten) will consume 4.8 amp-hours (Ah) per
>>> day.
>>> So if your numbers are correct, and if you wanted to never discharge
>>> your
>>> deep-cycle batteries too deeply (say never less than 80% discharged
>>> so
>>> they last longer), then a five-day run of (call it) 5Ah per day would
>>> require 25Ah, and a battery with a 30Ah rating should do the job.
>