120V power supply for 12V bunk warmer?

[saburai]

Hi Gang,

A little help here if you would...
I've got a Electrowarmth 12V bunk warmer that draws, according to the website: "6.2 amps maximum when the Comfort Control is cycled on, actual amp draw is estimated at 50% of maximum". What I'm attempting to do is power the bunk heater with 120V via the appropriate 12V power supply. So the question is what does the power supply need to be rated at?

Many thanks...

 

[LandCruiserPhil]

6.2amps x 12volts = 74.4 watts

100 watt power supply

 

[saburai]

Hi Phil, Thanks for the help. Would some thing like this 90w variable laptop power supply work? I already have it, I'd just have to make up a cable with a lighter plug. Here's a link to the unit I'm talking about:
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3254762&CatId=608

 

[saburai]

The power supply I have (above link) is 14V. Will the extra two volts harm the the bunk warmer?
Pardon my ignorance...

 

[LandCruiserPhil]

If Im reading the spec's on the right unit I see 14V as a min and up to 17V - not good

I would look to a 12v regulated power supply with over current protection. Your blanky will last longer with no worries of overheating it. Safety while sleep would be my main concern.

http://www.ebay.com/itm/12V-10A-Pow...lectrical_Equipment_Tools&hash=item3f0abedbfa

 

[saburai]

Thanks again Phil, def want to sleep safe. Would a laptop PS of the correct voltage be O.K.?

 

[saburai]

Anyone?b

 

[wrcsixeight]

I just got a 12 volt mattress heating pad as well. I had never thought to hook it directly to a 120/ 12 volt transformer, but when I do have access to grid power, I am running my battery charger all night long.

It is a Schumacher "intelli'charger with 2 12 and 25 amp settings. It will go into fault mode in the 2 amp or 25 amp setting when the mattress pad cycles on and off, but on the 12 amp setting it will top off my batteries while the mattress heating pad cycles on and off all night.

I do not know if this is an option for you. Since my "twin" sized pad draws 6.2 amps as well, and most wall wart transformers are rated for 2.5 amps or less, I think you need to get a burlier product if this is intended for use in the home, otherwise see if your battery charger can act as a converter.

 

[saburai]

Thanks! Do you have a link to the charger you use?

 

[wrcsixeight]

http://store.boatandrvaccessories.com/f044.html

While I have used this charger a lot, I do not particularly think it is a great charger. The Fan is loud, and sometimes the charging voltage spikes way too high. I do not think they make this particular model anymore and the link is old stock.

The charging voltage see saws from 14.1 to 14.8 when the mattress pad cycles on and off. The Fan on the charger speeds up and slows down very noticeably.

I cannot say which other " smart" chargers would allow the cycling mattress to not send it into fault mode, but this one does work, but only when on the 12 amp setting. It only starts out at 12 amps, as the battery charges, the amps taper fairly quickly.