12 volt??/inverter??

[Slim]

Just picked up my new respirator (gizmo I have to wear at night to help with breathing) anyhow the old one was mains 240v and I used my inverter but the new one is 12 volt with a 240v to 12v converter, I asked the tekkie bloke that demonstrated it if it would work direct off MH battery,the answer was... mmm er use a inverter, but if it does work direct,which would be most economical on the battery? and would i be able to buy an appropriate lead?.Thoughts please.. ...maybe someone else uses same??

 

[robjmckinney]

12 volt??/inverter

Clearly using it direct to battery would mean less power, small loss through the coverter but is it realy 12volt DC. It could be 12 AC, pulsed 12 DC and variations in between especially polarity so it may be worth a email to the manufacturers to be safe side!

Doubtful any tech salesman would know their business these days beyond instructions booklet!

 

[bob690]

Just picked up my new respirator (gizmo I have to wear at night to help with breathing) anyhow the old one was mains 240v and I used my inverter but the new one is 12 volt with a 240v to 12v converter, I asked the tekkie bloke that demonstrated it if it would work direct off MH battery,the answer was... mmm er use a inverter, but if it does work direct,which would be most economical on the battery? and would i be able to buy an appropriate lead?.Thoughts please.. ...maybe someone else uses same??

hi slim, be careful with your device, you should be ok on just the battery, but if youre on hookup, ie charging batterys at same time, you can fry certain electronics. Found this out to my cost. See maplins website they sell all sorts of devices for smoothing voltage etc.

 

[bigtrev8xl]

Hi Slim.
I use my new CPAP machine on 12 volt, just run it through a 12 volt regulated power supply.

Cheers Big Trev.

 

[Belgian]

Just picked up my new respirator (gizmo I have to wear at night to help with breathing) anyhow the old one was mains 240v and I used my inverter but the new one is 12 volt with a 240v to 12v converter, I asked the tekkie bloke that demonstrated it if it would work direct off MH battery,the answer was... mmm er use a inverter, but if it does work direct,which would be most economical on the battery? and would i be able to buy an appropriate lead?.Thoughts please.. ...maybe someone else uses same??

To my, humble opinion it should work direct on your battery 12 V DC. I've never heard anything should need 12V AC. Only watch the polarity; (if it sucks instead of blowing you have to change polarity ). All 12V appliances working with electric heating or el motor use DC (continuously or flattened)
No invertor needed anyhow. Connect directly to your battery.

 

[Deleted member 207]

If my memory serves me right and the device has the "CE" stamp on it, the wiring should conform to EU standards (is there such a thing?) - round plug the centre is positive and the outside is negative, any other arrangement should be marked with what is neg/pos.

 

[Slim]

thanks everyone for the info..tried it with a borrowed lead and it worked fine just have to get myself a lead now (bobably maplins?) I didnt want to jump in with both feet without testing the water if you get my drift.

 

[Deleted member 3011]

There can be a big difference between 12V DC from a plug pak and that from an RV 12V system and it could void your warranty to use other than the supplied powerpak.

Reason is that when you are on shore power and charging your battery, you could have anywhere up to 14.5V DC - and if you have flooded-cell batteries and run an equalisation cycle, you will get up to 15V DC.

Yes, your CPAP machine may work perfectly hooked direct to the battery and may continue to do so for a week or a month, but may eventually give up coping with a voltage 25% higher than it was designed for. There is no way of telling how it will go long term unless the manufacturer is willing to guarantee it

One way to reduce the risk is to run it through a forward-biassed silicon diode or appropriate current rating. This will reduce the voltage at the machine by about 0.7V - or 1.4V if you use two in series.