Mike C Posted April 19, 2005 Share Posted April 19, 2005 The 2 available 12v plugs do not supply enough current to drive my laptop through an ac inverter. Any ideas as to where/if I can tap into another 12v line that can handle the extra juice? The same setup works on a Honda CRV, just not on my legacy. Thanks, Mike C. Link to comment Share on other sites More sharing options...
meier motor sports Posted April 20, 2005 Share Posted April 20, 2005 how about run something straight from the battery Link to comment Share on other sites More sharing options...
mwiener2 Posted April 20, 2005 Share Posted April 20, 2005 Yeah, those two spots are gonna have the highest amp draw capability that are pre-wired. If you need more, you're gonna have to go custom. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
richardg1952 Posted April 20, 2005 Share Posted April 20, 2005 Is there any way to activate either of the two ports without the key on ACC? Link to comment Share on other sites More sharing options...
D-2.5-GT Posted April 20, 2005 Share Posted April 20, 2005 it probably has a turn on lead going to the ignition. you should be able to bypass it somehow. Not sure off the top of my head how or where, but it would certainly be possible. However if you can't get the current from those two slots, you might as well just run another line and set it up to be permanently on. Kill two birds with one stone. Link to comment Share on other sites More sharing options...
dustinw Posted April 20, 2005 Share Posted April 20, 2005 What kind of laptop are you running? I wouldn't think the draw from the inverter would be more than 7 amps for a laptop. So the cig lighter can't supply 7 to 10 amps? Or is your laptop seriously power hungry? Link to comment Share on other sites More sharing options...
Mike C Posted April 21, 2005 Author Share Posted April 21, 2005 It's a cheap Dell laptop. I wired up a switch box that ran directy off of the battery, and no dice. My wife's CRV must have a more robust alternator that can handle this much draw (I also couldn't power it directly off of the CRV battery, only the 12v outlet in the dash). I'm also surprised that the laptop is this power hungry. I even powered it on with the battery, and then connected it to the ac inverter once it was powered up and it didn't even recognize the ac was connected. I'm going to give my friend's laptop a shot and see if it behaves the same way. Thanks for the feedback! Link to comment Share on other sites More sharing options...
D-2.5-GT Posted April 21, 2005 Share Posted April 21, 2005 Be careful and make sure its all the way plugged in. Sometimes those slots are fussy about letting the plug make good contact. I know i have been having some trouble with a cell phone charger inching its way out in this car. Link to comment Share on other sites More sharing options...
ChE Outback XT Posted April 21, 2005 Share Posted April 21, 2005 Mike C - The laptop power brick should indicate its power draw. Hard to believe it would be too high for the battery. Could it be the brick itself? I once fried one on a crappy old army barracks power outlet (in Switzerland)... made it very finnicky about power. Link to comment Share on other sites More sharing options...
dustinw Posted April 21, 2005 Share Posted April 21, 2005 Well, there's a couple of things that could be going on. Using the cig lighter connector is definitely a low current option. And the plug may not be making good contact. Is the inverter itself powering on when plugged in? If it didn't work when directly connected to the battery then something else is wrong. It should always work when directly wired to the battery with good short length wires. What rating/brand is the inverter. Some inverters can play havoc with switching ac adapters, the modified sine wave causes the efficiency of the adapter to go down. If the stepping on the sine wave is bad enough out of the inverter, the adapter can overheat and fry itself. Link to comment Share on other sites More sharing options...
Mike C Posted April 21, 2005 Author Share Posted April 21, 2005 Dustin, you may be right, another odd thing I noticed is that when I plug in the ac adapter to the inverter (w/o the laptop connected), I can't even turn on the LED on the adapter. The status LED on the inverter starts fading in and out (as it did with the laptop connected). What bothers me is that this works in my wife's car, and also the fact that I can plug other ac appliances into my vehicle (such as a fan or a clock) and they work. I'll post some more detailed specs tonight, but I do know offhand that the inverter is rated for 150W. Link to comment Share on other sites More sharing options...
dustinw Posted April 21, 2005 Share Posted April 21, 2005 A 1A draw at 120V is 120W, and that's assuming no loss in the wires, or lost efficiency of the adapter due to stepped sine wave. Basically you are running right to the edge of the envelope. Any problems will be likely to show up in that scenario. Link to comment Share on other sites More sharing options...
Mike C Posted April 21, 2005 Author Share Posted April 21, 2005 One of my co-workers brought in their inverter which is also 150W (he bought his at radio shack) We also compared the ac signal on both devices on a scope and saw that mine (which doesn't work) is a square wave, with about a 20% duty cycle, the radio shack one is not quite a square wave, but there is some distortion to the signal that makes it appear more sinusoidal. In short, Best Buy sucks, and I'll be using the radio shack one. Thanks again for your feedback! Mike Link to comment Share on other sites More sharing options...
boris Posted April 21, 2005 Share Posted April 21, 2005 Looks like you got it figured out, but you could also get a car adaptor from Dell, or Ebay and leave the inverter out of the equation altogether. Link to comment Share on other sites More sharing options...
dustinw Posted April 21, 2005 Share Posted April 21, 2005 Looks like you got it figured out, but you could also get a car adaptor from Dell, or Ebay and leave the inverter out of the equation altogether. They usually cost 2x at least what a decent inverter costs. And it only powers that laptop. I've had good luck with Xantrex stuff: http://www.xantrex.com/web/id/6/inter.asp Thier consumer grade stuff isn't any more expensive and it seems to work well. They have high end stuff too, with true sine wave output. If you want to shell out the $$. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.