revisiting battery operation

[greatunclebill]

with this hurricane possibly aiming at the upper gulf coast and us in the middle i'm thinking about using the cpap's if the power dies for a few days. is it possible to run my machine off of a car battery? has anybody done it? all i should need is the proper plug for the cap, wire to the battery and a clip for the battery terminals. i'm wondering if the car battery even though it is 12 volts would be too strong and blow out the 12 volt cpap. i'm not real up on the amps part of it.

i know about recharging the battery and all that with 2 cars and a lawn mower, the neighbor on one side with 3 vehicles and the other side with 3 vehicles and boats, we can get it done.

should have bought the generator.

[Goofproof]

As long as you get the +/_ correct you will be fine. You didn't buy a Resmed so you are in. JIm

More AMPS won't harm anything as long as you have a fused line and don't over voltage it or reverse the +/_. Bigger just means it will run longer. I bought a little gas gen from China, but don't know it I could start it. 800 watts, just sitting in the bedrooM in case that hurricane gets to Indiana. Jim

Hurricanes are Gods way of getting even for the heating costs in Indiana.

[greatunclebill]

like my northern relatives say comparing blizzards and hurricanes. blizzards are cold and all the snow that goes with it but they normally don't take your home away like a hurricane can. i spent many years at an air force base near champaign, il, so i am familiar with your weather and heating bills. the thing i remember most is the bare black fields with all the snow piled so high on the roads they had to clear it with front end loaders.

this is the east central illinois i remember. this is us highway 45 after a big storm.

[robysue]

i spent many years at an air force base near champaign, il, so i am familiar with your weather and heating bills. the thing i remember most is the bare black fields with all the snow piled so high on the roads they had to clear it with front end loaders.

I spent part of my early childhood in Champaign and then returned for grad school at UIUC and stuck around for another 8 years and I developed a real attachment to east central Il. Thanks for the memories and that picture of 45.

[SleepyToo2]

[quote="Goofproof"I bought a little gas gen from China, but don't know it I could start it. 800 watts, just sitting in the bedrooM in case that hurricane gets to Indiana.[/quote]

Just don't run that gas generator in the bedroom - if you do, you won't need to worry about power outages for very long! Or CPAP, or anything else! I would be concerned about having the smell of gas in the bedroom at any time, but maybe that is just me. I looked at a gas generator option for the house, but there are restrictions on where and how you can run them around the house. Not in the garage, not in the house (or within at least 5' of the house), not standing in water, not in the rain ... makes it kind of hard to find somewhere to locate it that is going to meet all of those criteria. Oh, don't run it through the night, don't refuel when the engine is hot. Don't connect to the house supply without a transfer switch ...

Are they really that difficult to use? I have a large battery that will get me through at least one night of CPAP, so the generator was more for connecting the refrigerator/freezer. It gets expensive when they warm up! I can do without the TV, computer, X-box (my son will be upset, though!).

[greatunclebill]

Just don't run that gas generator in the bedroom - if you do, you won't need to worry about power outages for very long!

i sincerely believe goofproof and every other member here is smarter than that. he says he's storing it in the bedroom and you think he's going to run it in the bedroom.

[wilsonintexas]

I would recommend taht you put the humidifier in bypas mode.... no heat. . That will suck a lot more battery......

[JohnBFisher]

If you (or someone you know) can use a few tools, you might find the following Battery Backup Design helpful to create your own battery backup system:

viewtopic.php?p=449334

This design puts the battery in a battery box, it keeps things securely fastened, it includes a float charger, and makes the whole arrangement much safer.

You can then connect battery to a power inverter and plug the CPAP into the inverter. Of course with Respironics units you can just purchase a 12VDC cord:

https://www.cpap.com/productpage/respir ... -cord.html

Hope that helps.

[feeling_better]

with this hurricane possibly aiming at the upper gulf coast and us in the middle i'm thinking about using the cpap's if the power dies for a few days. is it possible to run my machine off of a car battery? has anybody done it? all i should need is the proper plug for the cap, wire to the battery and a clip for the battery terminals. i'm wondering if the car battery even though it is 12 volts would be too strong and blow out the 12 volt cpap. i'm not real up on the amps part of it.

i know about recharging the battery and all that with 2 cars and a lawn mower, the neighbor on one side with 3 vehicles and the other side with 3 vehicles and boats, we can get it done.

should have bought the generator.

I do not know your machine's specs. Has that got a 12v dc input? If so you are in luck. I have used a car battery as a backup for power failures; but I did not have to deal with more than a couple of hours power failures at a time.

Here are some suggestions:
1. Unless a sealed type, most car batteries do produce toxic fumes; so you want that outside the house, with nice long chord to your bed. Of course, if you are planning to double duty the one in your car or boat, it is already out of site

2. For many cpap models you can simply connect the battery to the dc power port, and the battery is in parallel (floating arrangement), and on a power failure the cpap wont skip a beat. This is surely the case if there is an external ac to dc power supply such as the M1 uses.

3. A fully charged battery may produce voltages greater than 12v (up to 14.4v or so). This would be above the spec of the machine; some models may tolerate it without any problem, but it is too much of a risk to take with the replacement cost of a cpap. I would add a couple of series diodes (5A or whatever the max current draw, especially on starting) so that the voltage is not too high. Ideally you can add a voltage regulator [a very low minimum votage drop type] that would provide the 12v from the higher voltage of the battery, and would keep it at that level even when the battery voltage drops to about 13v.

4. This is not something you asked about: These days if you hookup 10 rechargeable NiMh C cells in series, and add an inexpensive NiMh charger, you can run your machine for overnight on this very light, no fumes, battery. You can go to D cells for even higher capacity, or use a lap top battery (LiIo). The latter (a generic model) can be purchased online from China relatively cheap.

There have been many threads in this forum talking about the measured current consumption of many cpap models, under different pressure conditions. Search for them.

[chunkyfrog]

Oooh, wall clouds, mammatus clouds. Awesome!

[greatunclebill]

thanks for all the ideas and replies.

it's all set. i went to radioshack and bought the below items. if the storm comes here, and it's still a big if, if the power goes out i'll bring the car battery in before bedtime and keep it out of the bedroom with my long jumper cables, then plug this mess in. hopefully it will power 2 cpap's thru the night without the heaters. about the 14V comment, my battery is charged to 12 volts and has always been. i put the meter on it to be sure. i also brought all this outside to the car and verified that it does work. when we get up i'll bring it back outside to re-charge it in the car. during katrina we were without power 3 days if i remember correctly. now we live literally across the street from a big new substation so if we go out, hopefully it won't be for long.

now i'm wondering if my 12 volt lawn mower battery would power these things so i don't have to haul the car battery around.

just an fyi for those that haven't experienced the saltwater rain from a hurricane. as the storm comes across water it literally picks up saltwater and throws it out as rain. after the storm is gone, i forget how long it was, the leaves all fall off the trees and alot of green stuff dies from having the saltwater rain on it. as it goes inland it stops picking up gulf water and you get regular rain i guess.

[archangle]

Unless a sealed type, most car batteries do produce toxic fumes; so you want that outside the house, with nice long chord to your bed.

Car batteries do NOT produce toxic fumes. You can spill acid out of them if you turn them over.

Lead acid batteries, including sealed lead acid batteries like gel cells or AGM batteries, can produce hydrogen if overcharged. In any kind of home system with one or two batteries, they won't produce hydrogen fast enough to become explosive, even if you overcharge them, unless you put them in a tightly sealed container.

In order to produce hydrogen from a lead acid battery, you have to "boil" the water away. It takes 18 ounces (over a pint) of water to make 2 ounces of hydrogen. Unless you're having to add a pint of water every week or so, you're not making enough hydrogen to matter.

Hydrogen is completely non-toxic, even in high concentrations, unless you produce enough hydrogen to crowd out the oxygen in the air. There's not enough water in a car battery to make enough hydrogen to do that, even if you could instantly turn it all into hydrogen.

A sealed lead acid, including gel cell and AGM, battery has a pressurized case and a hydrogen recombiner to take care of a small amount of hydrogen. If you overcharge them enough to make a significant amount of hydrogen, it will overwhelm the recombiner, and the pressure vent will open, letting out a lot of hydrogen all at once instead of a little bit at a time.

Now, if you hook the battery up to some runaway power source like an arc welder or it shorts out internally, starts boiling, and explodes from steam pressure and heat, you could throw steaming sulphuric acid and lead all over the place. Sealed lead acid batteries will explode the same way as a car battery if that sort of thing happens.

[greatunclebill]

so, do the cpap's draw enough juice to drain the car battery overnite? i ask this because i'm wondering if the lawn mower 12v battery thats like a little car battery would handle the load. its on a 16.5 hp craftsman 42" cut.

[Sloop]

Why not kill two birds with one stone? Get a very powerful Jump Start battery that also serves to run your CPAP when needed.

Look at my setup.

[Goofproof]

Just don't run that gas generator in the bedroom - if you do, you won't need to worry about power outages for very long!

i sincerely believe goofproof and every other member here is smarter than that. he says he's storing it in the bedroom and you think he's going to run it in the bedroom.

Maybe if things get a little tougher. I was a heavy mechanic for 45 years, but now due to health, might not even be able to make the 800 watt gen run, should start it, but gas is hard to deal with, everything has to be drained when done using, and fresh gas is needed, so I just oiled it up. and sealed it back up. 800 watts won't do much, but it only weights 38 lb, that's about all I can handle. I have two small freezers with cow in them, hope it will run one at a time, don't think it will do the fridge. I'd also use it to charge the xpap battery with a 20 amp battery charger. I feel that things will get so bad soon, nothing will matter, I have it and guns, probably won't be able to use either effectly when needed. Jim