Power Converter

   / Power Converter #1  

Reddcow

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Hi, I am trying to hook up a power converter to my car, well not to my car but IN my car. I have a 1200W converter that was made to be put on the battery. But I need one that is going to plug into my smokers outlet. Is there anything of that high Wattage to go into a smokers outlet? I seen 800W one that would but I haven't seen any higher Wattage ones like that but wouldn't see any problem in doing do. Or is there a converting method I can use? Where instead of hooking it to my battery maybe there is a DC outlet I can hook it to, so it can go into the car?

Please help me, I really need the help. I am trying to hook a 1/2HP Transfer Pump and Pressure washer to it. Which Wattage I have no clue of, but know the 1200 would have worked I'm sure.

Thanks.

-John
 
   / Power Converter #2  
You can wire anything up you want... it doesn't mean it is a good idea.

The notes I'm seeing indicate that cigarette lighters are about 10A. The fuses are typically 15A fuses.

12V x 15A = 180 VA (W).

There probably is no sense plugging anything more than a 200W, or so, inverter into your cigarette lighter.

At 1200W.
That gives you:
1200W / 12V = 100A.

Technically you should use pretty big wires to handle that kind of amperage. Thus it must be connected directly to your battery, alternator, or starter (fused if you wish). Your cigarette lighter may be able to supply a little power, but you certainly wouldn't want to run a high power application with such a connection.
 
   / Power Converter #3  
Running a pressure washer from a inverter?
Go to the store and pickup a 2000W inverter generator and forget about a 12V mobile inverter over 200W plugged into a lighter socket.
It's all as Clifford has stated.
 
   / Power Converter #4  
You can wire anything up you want... it doesn't mean it is a good idea.

The notes I'm seeing indicate that cigarette lighters are about 10A. The fuses are typically 15A fuses.

12V x 15A = 180 VA (W).

There probably is no sense plugging anything more than a 200W, or so, inverter into your cigarette lighter.

At 1200W.
That gives you:
1200W / 12V = 100A.

Technically you should use pretty big wires to handle that kind of amperage. Thus it must be connected directly to your battery, alternator, or starter (fused if you wish). Your cigarette lighter may be able to supply a little power, but you certainly wouldn't want to run a high power application with such a connection.

100% correct. My 1,200 watt inverter is wired with 1/0 copper heavy shielded cable rated for inverter. massive wires and as short of run as possible.
 
   / Power Converter
  • Thread Starter
#5  
What about the ones that are 800W? Why do they sell them if they would cause a problem? Just curious.

Thanks

-John
 
   / Power Converter #6  
Yes...
At peak,
800W / 12V = 66A.

Even dropping down a bit, 50A or so should be using about 6AWG wire. You don't have that going to your cigarette lighter. And a pretty big fuse.

Now, if you are running a laptop computer, it is rated for a couple hundred watts, and should be fine.

Perhaps you should think. If you are using it inside the car, a cigarette lighter may be ok. How much power are you using inside the car?
But, if you are using it outside the car, at least go with alligator clips to the battery, or better would be permanently wired to the battery.
 
   / Power Converter
  • Thread Starter
#7  
Wait, how do you permanently wire to the battery? Is it bad for the battery? and I'm trying to power a pressure washer and a transfer pump, but don't think I need a transfer pump now. Is it bad for the battery too?

Thanks

-John
 
   / Power Converter #8  
It all depends on what you're doing and your situation.

Some deep cycle batteries have 4 battery posts and are the easiest to use. Just attach your inverter to the two unused posts. If you have screw-on terminals, just add your cable to the screw, use a longer bolt if necessary. If it is a normal clamp on terminal, you may need to replace the battery connector. As was mentioned, if the frame of your vehicle is grounded, you can just clean a contact spot to bare metal and connect the ground cable to the frame, anywhere. Or you can also connect it to the battery.

We talked about basic conversions, which you can use to convert from 120V to 12V.
Watts = Amps x Volts

Keep in mind that many tools only show their peak power rating, which may not be representative of the power you will see when using it. Use an inductance ammeter over one leg in an AC circuit to verify.

Some inverters will also have a peak power and continuous load rating.

Car batteries don't like to be drained. Deep Cycle batteries will take draining somewhat. But, all batteries will have an Amp-Hour rating, although it may be hard to find sometimes. A car battery would be rated at about 50AH x 12V. If you are doing a 100A draw for 1/2 hour, it could more or less completely drain the battery. For high power applications, you will likely want to keep your vehicle charging the battery.

With a 2 battery configuration, you can use a battery isolator to prevent your "start battery" from being drained.
 
   / Power Converter #9  
Wait, how do you permanently wire to the battery? Is it bad for the battery? and I'm trying to power a pressure washer and a transfer pump, but don't think I need a transfer pump now. Is it bad for the battery too?

Thanks

-John


Please elaborate on where, when and for how long on a transfer pump or a pressure washer.
As previously stated, 175W continuous load from a cigarette lighter socket is absolute max.
How large is the alternator on your vehicle?
 
   / Power Converter #10  
Another option to consider (cheap) is a set of jumper cables. Cut off one end and wire to inverter dc input (red + /black -). Clip the alligator ends to your battery when you need it.
 
 
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