Car Cig lighter DC to AC output MAX?

Question

I need to run an xbox 360 in my car. I need a DC to AC invertor that can 1.plug into cig lighter 2.Have enough power to run the 360.

Note: I have a 450W, plugs into cig lighter. Does not have enough power to run the 360.

I already assume i'll have to run cables from my battery.

Answer 1

This website says an xbox 360 uses only about 160 watts:

http://reviews.cnet.com/4531-10921_7-639...

So a 450 watt inverter (an inverter changes 12 volts dc to 120 volts ac) should work fine.  Just make sure it really is a 450 watt inverter.  Here is a 400 watt one:

http://theinverterstore.com/the-inverter...

Your unit should look simular to this one.  You may have a inverter that claims to put out 450 watts but really is not that powerful.

A good quality inverter of at least 200 watts capacity will work fine.

Yes, "Wires" is right - I wasn't thinking it through.

Answer 2

I'll try and clarify and hope I don't add to the confusion.  

If your 360 draws 160 watts when it's on, that is about 1.3 amps from 120 volts.  But to get the same 160 watts from 12 volts you would draw just over 13 amps.  You can't compute current from watts at 120 volts and apply that current to 12 volts.  You'd only get 1/10 the watts.  So the 360 would draw 13.3 amps from 12 volts, plus some circuit inefficiencies in the inverter so you're looking at more like 15 amps or even more.  

The cigarette lighter plug in a car is only fused for 10 or 15 amps.  If it is 15 amps you'd really be pushing the fuse to draw the full 15 amps through it.  It wouldn't blow right away but wouldn't last long.  Of course if it has a 10 amp fuse it would open very quickly.  

So, yes, run the wires directly to the battery.  You could probably use 14 gage wire, but 12 gage would be better.  Not as much voltage drop in the wire itself.  Put a fuse in the hot wire within 18 inches of the battery.  If the wire shorts, a fuse at the inverter won't help.  You need to fuse it as close to the power source, the battery, as you can if you want the fuse to do it's job.  Your 450 watt inverter should run the 360 fine if that is it's true capacity rating.

Answer 3

The surge current into the converter probably blew the fuse or tripped the breaker in cig lighter circuit.  Check that out first.  I'm not a gamer so I have no idea what an xbox draws.  I would be surprised if it is more than 120W or so, i.e. 10 Amps at 12VDC.  If you have a 450W DC to AC converter it seems to me that it should be more than sufficient.  450W equals 37.5 amps at 12V.  I think the accessory outlet or the cig lighter outlet of your car are fused for 30 Amps max.  I am surprised it didn't work for your xbox.  The converter must have a lot of inrush current to charge some capacitors.  

Yes, I think it will be best to make a direct connection to the battery.  Be careful how you route the cables.  It is best to go through the firewall even though it is a lot of trouble.  Do not route it to come up through the floor.  That is a bad fire risk.  You do not want a fire at 70 mph.  The audio installation guys at Circuit City said that they would install the cables through the fire wall for a modest cost.  Probably worth it because they do it all the time and know the best and safest way.  I wanted the direct battery connection for my ham equipment.

Check the specs for the xbox in the instruction book and post the power consumption data as an edit.  You will get a better answer.