I sleep with a CPAP machine as a medical necessity. Can anyone suggest a way to supply it with power indefinitely? It runs on about 120watts x 8 hours per night. It has a DC input, so no inverter loss to worry about. As far as I can tell, I'll be drawing 960 watt hours / night, so I'll need an efficient way to provide that or charge back a battery bank each day. Solar? Wind? any suggestions are welcome.
Since this got no replies and I found a solution, I'll chime back in. Bought a 75AH deep cycle battery for use with my 1000 watt modified sine wave inverter. This works fine if not using the humidifier (in which case, you need a pure sine wave) and should last me about 5 nights. The whole thing got me thinking of what to do if the power is out long term. I think those of us on powered medical equipment should devote a serious effort to finding a workable solution that doesn't require power. In my case, that would be one of those anti-snoring mouth pieces. So working that out is on my list of prep things to do.
Just a thought but you have the battery so why not a solar charger or one of the home made chargers out of an alternator and a small motor . Ya know two batteries would work ,charge one and use the other !!
Yup, that's the (eventual) plan. One catch is that the machine eats up about a kilowatt hour per night. That makes for a lot of solar and/or wind needed to maintain those batteries. Seems like right now, anything over a 40W solar charger costs big $$$.
Anything can be worked out . I think a small engine with a alternator would recharge your batt. in a few hours or less ,there are many plans out there for something like that . I'd just put a grandson on a bicycle with an alternator on the back wheel ,ain't it funny how a teenager never runs out of gas !!!!!!! LMAO I'll look around and see what I can come up with,I know how hard it is to sleep without one .
Thanks Cephus! I actually made a generator out of a lawnmower engine with a belt drive to an old Ford alternator. I worked ok, but the shaft on the engine was bent and it rattled a lot so I don't expect it would have run for more than a few hours in an emergency. I've since purchased a ChiCom generator. Still running, but not my best purchase since parts can no longer be found. I plan to get a better one and convert it to LP gas to work out at the retreat. I think the real answer for anyone that needs to run an engine in a crisis is wood gas generation. Building a wood gas generator is CHEAP AND EASY if you can weld. Ironically, all the info you'll ever need is provided by none other than FEMA!!! Google "FEMA wood gas" it should get you to the PDF.
Sounds a good plan to me ya know Harbor Freight has a 10 KW (just the head no engine) for just under $300 I know a guy that has one and he has only good things to say about it ! It needs a 20 hp to run it for full effect but with wood gas that shouldn't be a problem .
Never heard of wood gas. THIS IS SO COOL. I'm building me one of these. Thanks for the knowledge. You can use grass clippings!!! Oh boy Oh boy
In a real TEOTWAWKI situation, gasoline and diesel will be hard to come by. Heck. During hurricane Fran, we had folks have their generators run dry, and when there's no power, the gas pumps don't do much. A pile of wood chips however has much BTU power and is cheap and easy to come by.
"Town gas" was another name for producer gas, which is a low BTU byproduct of coke (and charcoal) manufacturing. (The other kind of town gas is a byproduct of bar hopping --)
