Using my 48V 15ah battery to run a CPAP machine

[overtonmath]

I have a CPAP for sleep apnia and want to use my 48V 15ah battery to run it. I think I need an inverter. What should I be looking for on the CPAP to tell me which inverter to get? And how long will my battery run the machine from full charge? The markings on the CPAP transformer that plugs into the wall says 60V. In smaller print it says 12V-5.0A

 

[Nanoha]

It's usually not a good idea to run things that your life depends on from an ebike battery but if you must then the machine draws 60w and your battery "should" have 720wh of energy. So assuming 100% efficiency of your inverters / dc dc converters, you should get 12 hours of run time.
Perhaps get a 100w dc dc converter to convert 48v straight to 12v so that you don't need to go through an inverter and the transformer?

 

[gogo]

The markings on the CPAP transformer that plugs into the wall says 60V. In smaller print it says 12V-5.0A

That's probably 60W and your battery has a maximum of 720Wh (48V*12Ah), so 720/60 =12 hrs. You probably shouldn't discharge your battery more than 80%, so 12(.80) =9.6 hrs. If you use an inverter, subtract more for that loss.

Your CPAP machine could expect a very specifically conditioned power source, so you want to look for information specific to your model. The manufacturer is a good place to start.

 

[overtonmath]

The markings on the CPAP transformer that plugs into the wall says 60V. In smaller print it says 12V-5.0A

That's probably 60W .

Your correct it is 60W not 60V

 

[dnmun]

do you know what types of components are inside? do any of them use AC? that is the important thing to learn first.

 

[wesnewell]

If the transformer has a 5A 12V DC output, just bypass it with a 12VDC input directly into the machine. Or better yet, just wire a 12V battery source in parallel with the transformer so it will take over if the transformer fails or you lose power. Although I would think it would have an internal battery already if it were a critical device. Putting an inverter on your pack is not the way to go. You'll lose efficiency going from through the inverter. A whole different story if the transformers out put is 12V AC.

 

[dogman dan]

Going on a road trip where there will be no plugs? You'd need a dc dc converter to get 12v from your ping. Or just get a separate 12v battery of some kind.

1 hour of operation should take no more than 60 watthours. 5 ah of 12v per hour. Your ping should have at most 12 hours operation in it.