How to run laptop or appliance off 12 v

[vaddisonme]

Hi,
Excuse my total ignorance of all things electrical, but I am hoping that someone could help me here. My car-go lite trailer has a deep-cycle marine battery and a "power Center" so that when it is plugged into shore power the A/C works, the battery charges. When it is not plugged in, the lights and fan run off the battery. There is one 12 volt plug in the back (I wish there was another up front!!!). In the manual I got with the trailer it talks about the "power center" and 110 volt system then says, "The next 15 amp breaker controls the 12 volt portion of the system". it lists the different circuits and what they are designated for including "GREEN circuit: 10 amp fuse, reserved for 12 volt outlet". So I gather that is the circuit for the one 12 v outlet.

So....I have an ipad that I would like to be able to charge even when we have no shore power. I also have a small dehumidifier with a fan that I would like to run that says "input, 9 volt 2.5 amp" on the back of it. Questions: Do I have the capabilities to run my little dehumidifier for 8 hours overnight? If so, how do I plug it into the 12v socket, since it has a regular plug on the end? What goes between the regular plug and the 12volt socket? Same for my ipad? How do I charge it with the 12 volt system and is it strong enough to charge it? (The manual says DO NOT OVERLOAD THIS SYSTEM!).
Thanks for the help.

[vaddisonme]

Just looked up my little Eva-dry dehumidifier. It says it needs 22.5Watts. ...

[vaddisonme]

and my ipad needs 5.1 volts, 2.1 amps, 10 watts. ????

[eamarquardt]

The easiest way to charge your IPad is one of these:

http://www.amazon.com/s?ie=UTF8&page=1& ... for%20ipad

I'm not really familiar with IPads (I prefer a netbook with a real keyboard) but I've gotta think the chargers above will work.

Using your dehumidifier is a bit more complex. Does it use a wall wart power supply? If so, does the power supply have a coaxial plug that plugs into the dehumidifier or is the cord "hard wired". If it uses a coaxial plug you can see what the voltage and current are and Radio shack sells universal power supplies that will supply any number of gadgets using a variable power supply and interchangeable outlet plugs.

Something like this: http://www.radioshack.com/graphics/uc/r ... _PM_EN.pdf

But I think there is one with more voltages and plugs.

If it is hardwired and runs on 120 volts into the unit an inverter will work but won't be that efficient.

If you provide more detail you can get more detailed answers.

Hope this helps.

Cheers,

Gus

[vaddisonme]

Thanks so much. Here's more info! The wall plugged power supply for the dehumidifier unplugs from the unit and has two little holes that the unit male posts plug into. It is a "Switching power supply" and says model YJSo24C-0902500U. Inout 100-240V~50/60HZ 800mA. Output:9.0V-2500mA.

The battery says AquaEdge 24DC-80. 80 Amphour. 475CCA 595MCA. 100 Res Min @25 Amps.

so... Is it possible to tell from this info if I have enough battery juice, (if I have a fully charged battery) to run my baby dehumidifier for 8 hours? thanks. I can see I need to educate myself in the intricacies of the world of electricity!

[jeffmutch]

The simple answer you are looking for is yes, you will have enough power in the battery to run the dehumidifier for 8 hours. Depending on how efficient your inverter is (the device that allows you to plug your existing power cord into the 12 volt socket on the teardrop), maybe longer.

Now, if you are looking at running the dehumidifier for 8 hours, charging your ipad every night, using lights and/or fans, or whatever else you have going, you will be cutting it close. To get the best lifespan out of your deep cycle battery, you should never discharge it more than 50%. This gives you about 40 amp/hours to work with. Just your dehumidifier will consume about 20 amp/hours. The inverter will probably suck another 8 to 10 amp/hours.

If someone else wants to do all of the official calculations for the Ipad and additional electronics, feel free, but those answers tend to confuse people...

Good luck!

[eamarquardt]

As was said, you have enough juice to run your dehumidifier but with your other loads you might be pushing it. 9 volts is a bit unusual for anything other than small do dads powered by 9 volt "transistor radio batteries". 2.5 amps is a bit more current than most little 12 to other voltage converters will handle (as far as I know) but there may be one out there.

How does your dehumidifier work? Just it just blow air over a gel or desiccant and then you replace the gell or desiccant or you set it outside or in a warm place to regenerate it? Maybe you could cobble something together using a computer fan (which would be 12 volt and use far less power) and a similar desiccant kinda like they did on Apollo 13 to MIckey Mouse the CO2 scrubber that allowed them to make it home.

More details, more suggestions.

Cheers,

Gus

[vaddisonme]

Actually, I have a dessicant one also. We like this one because the fan blows the right amount of white noise, and if it is cold and there is a lot of humidity settling on the cold window frames, it reduces the amount of condensation. I don't have to have it on. I was jsut wondering if I could run it using the 12 v socket. I guess I will stick to just using the 12v ti charge my ipad!

[vaddisonme]

And use the plugin EVA-dry when we have shore power!

[kludge]

Re: the iPad

If you can get one of the cigarette lighter to USB converters, then you just use the USB cable that came with your iPad. eamarquardt already linked you to some of those. I will just say, try to get one that is "Made for iPad" as that is Apple certified to work with iPad. The Apple certified devices list the Apple products for which they are certified on the box and/or in the literature.

I use a little Griffin brand USB socket in my truck for when I'm running the GPS on my iPhone or for overnight charging when I'm camping with the Scouts. Even if you don't get the full 2.1A (10.5W) it will still charge, it will just take longer.

Re: the dehumidifier, a cigarette lighter type socket will have plenty of power to run the dehumidifier if you can find a 12V to 9V dc-dc converter.

Here are a couple I found after a quick search:
http://www.thenerds.net/LIND_ELECTRONIC ... ml?affid=3
http://azsurplus.com/index.php?main_pag ... ts_id=1755