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Re: Traveling in a motorhome with CPAP
Posted: Mon Jul 05, 2010 7:55 am
by Patrick A
linda12345 wrote:Okay, so I will not use the CPAP while driving. Very good advice..........
Tonight is the big night. From what all of you are saying, I should have no problem. The fact is that I have 4 batteries at 225 amps each. Using the " simple " formula and calculating at 180 watts, that is 15 amps. If I sleep for 7 hours, that is only 105 amps...........plenty of battery power.
Have a happy 4th,
Linda
linda I hope you had a great night of sleep I would suggest that you read this
http://www.marxrv.com/12volt/12volt.htm
Re: Traveling in a motorhome with CPAP
Posted: Mon Jul 05, 2010 9:00 am
by SleepyTiger
SleepyInSeoul wrote:As an electrical engineer...
(b) If your battery's capacity is 200 amp-hours, then it would run for 20 hours on the battery (10 amps x 20 hours = 200 amp-hours)
In THEORY your 200 amp-hour battery will provide 20 hours.
However in PRACTICE it is very bad for the battery (even the deep-cycle types) to draw them all the way down to zero.
The rule of thumb for deep-cycle batteries is to never discharge them more than 50%. (The ResMed battery page also indicates this). Thus 100 a-hrs out of a 200 a-hr battery.
S/T
Re: Traveling in a motorhome with CPAP
Posted: Mon Jul 05, 2010 6:11 pm
by SleepyInSeoul
SleepyTiger wrote:
In THEORY your 200 amp-hour battery will provide 20 hours.
However in PRACTICE it is very bad for the battery (even the deep-cycle types) to draw them all the way down to zero.
The rule of thumb for deep-cycle batteries is to never discharge them more than 50%. (The ResMed battery page also indicates this). Thus 100 a-hrs out of a 200 a-hr battery.
S/T
SleepyTiger - thanks for posting this. I just gave some simple theoretical calculations, as I stated. Your point is well noted.
Re: Traveling in a motorhome with CPAP
Posted: Tue Jul 06, 2010 5:46 am
by linda12345
Hooray! Great night sleep. No problem with the batteries....last entire night with much room to spare. Thanks to all of you who gave me information and advice. Without you, I probably would have been up all night worrying about the batteries. And even more, I now understand the electrical/battery system a little better.
Linda