Geary,
Since the amperage is the same (2.5) for
both 110 v and 12 v, my guess is the machine is
running on 12v and has an internal transformer to
cut down mains voltage. That being the case, it
would be rather inefficient to use an inverter to
raise 12 v to 110 only to cut it back down to
12. Much better to get the 12-volt cord and run
directly off of the battery. Most modern
motorcycles are 12 volt. You'd need to know the
amp-hour rating of the battery to calculate how long it would last.
An easy way to keep your motorcycle or
car battery charged in the field is with a
briefcase solar panel like this one
<http://www.amazon.com/S-1116-12V-Briefcase-Solar-Generator/dp/B0018SC1SW>.
I have used such a panel coupled to a car battery
on a two-week caving trip to Mexico where we were
completely off the grid. The panel kept the
battery charged the entire time, and we charged
many things off of it (caving lights, drill
batteries, GPS, walkie talkies, etc.), including
some that needed an inverter. Any motorcycle
battery should work well coupled with such a
solar panel, which should work especially well in Death Valley.
Mark
At 11:37 AM 11/18/2012, Geary Schindel wrote:
Folks,
Sue and I are heading out camping this
Thanksgiving and have a camping/caving related
question for the electronics gurus in the group.
Sue has a sleep apnea machine she uses. Weve
used a marine battery that has worked for as
long as a week without charging. I checked the
amp hour rating of the battery and compared it
to the demands of the machine but Im not sure I
got it right or was just lucky. On this trip,
were flying out to meet Graham and Aspen and
going camping in Deaf Valley Thats Death
Valley, just checking to make sure youre
listening. Flying with a 70 pound marine battery
probably isnt a good idea. Anyway, we were
thinking of purchasing a motorcycle battery from
Autozone in a nearby town and was wondering if
folks think the battery would last for three nights without charging.
We use an inverter connected to the battery to
power the machine. The machine is a
Resmed. The specs are AC 100-240V 50-60
hz. 110v 400 hz, 2.5 a. DC 12 V 2.5 amp.
I didnt see the DC connection before so Im
wondering if I can get a 12 volt DC cord.
Anyway, Im not familiar with motorcycle
batteries and dont know whether they are 12 v
or 6 volt and how many amp hours they
are. Anyone have some suggestions as to what they do.
Thanks
Geary,
P.S. if youre thinking about breaking into my
house and robbing me of my vintage caving
coveralls with real canvas grip patchs (a real
collectors item), we will have a full time housesitter and visiting friend.
Please reply to mmin...@caver.net
Permanent email address is mmin...@illinoisalumni.org
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