Hybrid Car for an emergency power source for CPAP?

LyleHaze · Post by **LyleHaze** » Thu Jan 03, 2008 2:43 pm

A few thoughts on the subject of running a CPAP off a car battery:

I recall reading somewhere that you should only do this with the engine OFF. This is probably because the voltage of a car battery while running is usually about 13.8 volts.. A bit higher than the voltage while switched off.

Some mention was made of lead-acid or gell-cell batteries for backup purpose. (with an inverter for humidifier use). Great idea, but I'd make sure the batteries don't off-gas hazardous fumes while charging or discharging.

I've said enough. You may now resume your Prius discussion.

LyleHaze

jules · Post by **jules** » Thu Jan 03, 2008 3:14 pm

please bear in mind

the teddy bear owner is the one who decided we should purchase the prius

Bearded_One · Post by **Bearded_One** » Thu Jan 03, 2008 4:47 pm

The Optimas are pretty good about not outgassing as long as they are charged slowy and are not overcharged.

I just found out about the "Lifeline" brand of RV deep cycle batteries that are totally sealed and have an expansion chamber, so there is no out gassing. Supposedly they can be used in any position.
http://www.lifelinebatteries.com/rv.php

Guest · Post by **Guest** » Thu Jan 03, 2008 7:20 pm

Goofproof wrote:
Roadie wrote:Laugh all you want. My wife has tracked the fuel costs, and about 3000 miles ago we broke even on the higher price of the car versus fuel savings. Plus the factor that the car makes far less pollutants than other cars makes us feel better about owning it. But, you are entitled to your opinion, just don't forget that I am also entitled to mine.

Roadie
Here is the mis-conception, True the Prius saves on fuel cost. It does not however lower polution, When you add in the polution from the production of the battery systems, far more serious polution is caused. So while all trys to cut polution are good, so far this fails the Green Test badly. Jim

ding ding ding... we have a winner here folks. I'm looking for the study that showed you save energy driving a hummer for 100,000 miles over a prius because of what it takes to mine the minerals

Goofproof · Post by **Goofproof** » Thu Jan 03, 2008 7:29 pm

And ship the minerals to Japan, to be made into Batteries, ship them to the U.S. again for production. Then later safe disposal of old ones. Jim

Roadie · Post by **Roadie** » Thu Jan 03, 2008 8:05 pm

Look, you can find a study to prove ANYTHING. I am not trying to say that driving a Prius is cleaner in every possible way. Heck, driving any automobile is far more polluting than walking. But, in one way that is easy to describe the Prius is cleaner than almost any other car, and that way is tail pipe emissions.

Everything has an impact. Eating an orange has an environmental impact. Was the orange shipped from California, Florida, South America? Should I stop eating oranges. What will the impact be when I get scurvy?

That Hummer does not just magically appear. Manufacturing it consumes resources, operating it consumes resources. Petroleum needs to be drilled for and refined. A vehicle that consumes far less petroleum to operate uses far fewer of this resource, and has a different impact than the Hummer.

I like my Prius for lots of reasons. Fuel economy, and pollutants are just two of the reasons. I like the styling. The seat fits my body well, and is comfortable for long drives. I like the interior layout. I like hatch back cars more than traditional sedans. It has lots of interior head and shoulder room and I don't feel cramped. The back seat has enough leg room that a 6 foot tall adult can fit there comfortably. It is easy to park, It has a nice tight turning radius. It is quiet when driving down the road.

Just because I like my Prius does not mean that I will impose my decision on you. You are free to buy any car you choose to, that is your business not mine.

I still think that any car including the Prius would be a poor choice as a planned backup power source for a CPAP machine.

Roadie

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Guest · Post by **Guest** » Thu Jan 03, 2008 8:09 pm

Hi roadie.

I wasn't implying driving a Prius is somehow against the rules. The notion of it having less of an impact environmentally though is something which, in the age where we freely exchange information, needs to be addressed.

Drive your prius, I'll drive my diesel.

ColinP · Post by **ColinP** » Fri Jan 04, 2008 8:21 am

I like my diesel too. And I also agree that using any vehicle's engine for a CPAP power supply is a bit of overkill, but I strongly suspect that if the Prius' battery is fully charged you should easily get a night or two without needing to run the engine to charge the battery.

I have no idea how many amp hours the Prius's battery is, but I was away in the bush for a week in December, and I easily ran my ResMed Spirit (off 12V, directly with no fancy cable or inverter, also no humidifier) for 4 nights on my 105 amp hour deep cycle battery before needing a charge. I topped the battery up using a solar charger for the next two days (using the CPAP again that night) and had enough charge to do the last two nights with ease. I suspect that the Prius's battery is much larger than the RV battery I was using.

After the four nights, the battery voltage was down to 12.4V, and I suspect I could have squeezed another night out of it if I needed to.

Colin

p.s. The holiday was good, even if my AHI is still way too high. Part of the problem seems to be getting used to sharing the bed again after years of having the part the cats don't use to myself. Maybe a king-sized mattress is called for, as between us there are now 5 cats