Inverter choice

scoobydiver

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I need to be able to run a CPAP machine in the van but we spend a lot of time off grid , I have 330amps of battery power charged by 340w of solar panels, problem is all new cpap machines are 240v max draw of 4amps , what inverter would you suggest and why and would you go for pure sine ? Tia
 
scoobydiver said:
Says 3.8 amp but that must be under full load , once it's set it will probably only run at 1.5amp but obviously don't want it to keep tripping inverter
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My own recommendation would be a Victron 12/500 Phoenix or maybe a 12/800 if you wanted more leeway.
the 12/500 is a 400W inverter; the 12/800 is a 700W inverter. The Reason why I would go for the Victron is they are designed to be able to run non-stop (I ran my 12/500 24/7 for over a year), they run silently (handy if you need them to be working when sleeping), they have a 5 year warranty so shows good confidence in product, and they have a good surge capability by design e.g. the 400W inverter can run at 900W for upto 30 seconds. Most inverters will have a very limited surge capability measured in milliseconds.
 
We questioned the hospital about 240v only and they ordered from the manufacturer a 12v input supply which is fine. Power consumption is nowhere near your suggested figures. It takes very little out of our 200w batteries overnight.
 
I have run my cpap with humidifier and heated tube from a Victron 12/500 without any problems. The cpap itself shows a max draw of 3.5 Amps but this is at 24 Volts. The mains power supply driving it has a max draw of 1.5 amps at mains voltage but even this is probably when being fed at 110 V rather than 230 V. In practice the draw from the 12/500 is very comfortably within limits of the inverter.
 
wildebus said:
My own recommendation would be a Victron 12/500 Phoenix or maybe a 12/800 if you wanted more leeway.
the 12/500 is a 400W inverter; the 12/800 is a 700W inverter. The Reason why I would go for the Victron is they are designed to be able to run non-stop (I ran my 12/500 24/7 for over a year), they run silently (handy if you need them to be working when sleeping), they have a 5 year warranty so shows good confidence in product, and they have a good surge capability by design e.g. the 400W inverter can run at 900W for upto 30 seconds. Most inverters will have a very limited surge capability measured in milliseconds.
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Thanks for that I'll have a look
 
Edward B said:
We questioned the hospital about 240v only and they ordered from the manufacturer a 12v input supply which is fine. Power consumption is nowhere near your suggested figures. It takes very little out of our 200w batteries overnight.
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They said the old machines used to be 12/240 volt but the new ones are 24/240 volt
 
wildebus said:
My own recommendation would be a Victron 12/500 Phoenix or maybe a 12/800 if you wanted more leeway.
the 12/500 is a 400W inverter; the 12/800 is a 700W inverter. The Reason why I would go for the Victron is they are designed to be able to run non-stop (I ran my 12/500 24/7 for over a year), they run silently (handy if you need them to be working when sleeping), they have a 5 year warranty so shows good confidence in product, and they have a good surge capability by design e.g. the 400W inverter can run at 900W for upto 30 seconds. Most inverters will have a very limited surge capability measured in milliseconds.
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Thank you
 
They gave me a 12v cable at the hospital but I only use the cpap fo r a few weeks it’s been back in it bag for the last several and the hospital are getting it back tomorrow can’t get away with it .the good news I’ve lost 2 st
 
Can I ask what dvla had to say about your sleep apnea.I just sent my licence off for renewal and am waiting to see what they say thanks.
 
DVLA must be notified of sleep apnoea for any type of driving license (not just C1). Provided your treatment is confirmed as effective by your medical people there doesn’t appear to be a problem. I notified them 15 years ago and received confirmation that I could continue driving without restriction. I checked with them last year that all was in order and they confirmed that as long as there was no deterioration I do not need to do anything until renewal at 70.

I am happy running my cpap from my Victron 12/500 inverter. I added a bluetooth dongle to it so that I can remote control it from my phone. I leave it on standby and just click it on when I need it at bedtime, keeps battery drain to a minimum.
 
Okta said:
DVLA must be notified of sleep apnoea for any type of driving license (not just C1). Provided your treatment is confirmed as effective by your medical people there doesn’t appear to be a problem. I notified them 15 years ago and received confirmation that I could continue driving without restriction. I checked with them last year that all was in order and they confirmed that as long as there was no deterioration I do not need to do anything until renewal at 70.

I am happy running my cpap from my Victron 12/500 inverter. I added a bluetooth dongle to it so that I can remote control it from my phone. I leave it on standby and just click it on when I need it at bedtime, keeps battery drain to a minimum.
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Thanks for that information
 
I noticed that my Phillips CPAP actually runs on a 12v dc output from its mains transformer.
So I got a suitable power lead (HP computer) free from a repair shop attatched a cigarette lighter type plug and run it out of a dedicated socket by my berth.
So no power losses going up to 240 and then back down to 12v.
I don't think that the consumption is as great as op fears.
 
Bear in mind that the 12V output from the mains transformer is a REGULATED and steady 12V DC
The output from a motorhome Leisure Battery is an UNREGULATED output of nominally 12V but actually anywhere from 11.5V to 14.7V depdending on what is going on.
Using that kind of supply on a device that is likely designed to expect and accept a strict 12V supply is asking for trouble. It may not fail immediately but it is not a clever idea unless you KNOW the unit can accept that level of fluctuation (I assumed these are not cheap either? Who pays for them if they break? I guess the NHS? in which case, it doesn't matter if they break as you can just get a new one, can't you? And saved the cost of an Inverter as well? Win-win :rolleyes: )
 
wildebus said:
Bear in mind that the 12V output from the mains transformer is a REGULATED and steady 12V DC
The output from a motorhome Leisure Battery is an UNREGULATED output of nominally 12V but actually anywhere from 11.5V to 14.7V depdending on what is going on.
Using that kind of supply on a device that is likely designed to expect and accept a strict 12V supply is asking for trouble. It may not fail immediately but it is not a clever idea unless you KNOW the unit can accept that level of fluctuation (I assumed these are not cheap either? Who pays for them if they break? I guess the NHS? in which case, it doesn't matter if they break as you can just get a new one, can't you? And saved the cost of an Inverter as well? Win-win :rolleyes: )
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Or just stabilise at 12v and save nhs money
 
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