Problem Solving

Hi all,

You may have noticed a new Pinboard, labeled Perpetual Sleep. As you may or may not know I was diagnosed this summer with sleep apnea, as a result I now need a CPAP machine in order to get a restful night sleep, the two things that are needed to operate a CPAP are distilled water and electricity.

Distilled water is an easy enough problem, as a gallon last me for about a week so two gallons of distilled water will last the length of a typical expedition. (~10-11 days) At home power is not an issue, however out in the wild I need to have a solution that will allow me to sleep for 10-11 days without plugging the battery into the grid. Hence, I have designed a system where the CPAP can run for a day or two without recharging.

It starts with a battery package designed for telescopes. (Hey, when you have a hammer everything looks like a nail.)  This gives me 2 nights of sleep for up-to 11 hours. Now in order to charge it you need a power source, something that outputs 12v at a reasonable amperage to charge a 17AH battery. So basically I want 12v at about 2 amps, which is 24W. Since you can get a 50W solar panel for less than $100 why not get more power than you need.

This gives me a system where I can sleep at night as long as there is not a couple of days without any sunlight. Now I can sleep the question is how are we going to carry along enough food and water to be in the back country for that long.

More generally, the abundance of cheap solar panels is an amazing boon for the end user, as it allows camp sights to be self sustaining, including powering electronics such as laptops and telephones. I hope to have about 400W of solar panels on hand for charging batteries and the like, along with this object which uses a Peltier to turn fire into electricity.