Power inverter, what do you guys use

How much pull would a 17" laptop have on a 400watt inverter? I saw a 800watt inverter, but didn't figure I would need that much power since I won't be running alot of stuff on it.

Look at the label on the charger, and it will tell you what its wattage is. Could be as low as 60 watts for a netbook to as high as 250 watts for a high end Alienware. I would take the highest wattage you would ever expect to need, and at least double it. This usually means 500 watts at the very least. Inverters are cheaper now than ever. No real reason not to have some power to spare.
 
Look at the label on the charger, and it will tell you what its wattage is. Could be as low as 60 watts for a netbook to as high as 250 watts for a high end Alienware. I would take the highest wattage you would ever expect to need, and at least double it. This usually means 500 watts at the very least. Inverters are cheaper now than ever. No real reason not to have some power to spare.

It's not an Alienware by any means. lol I had a Desktop gaming machine built about 8 years ago by Alienware, that thing was a beast for it's time. Too expensive to maintain a gaming machine and keep it up to date, when I can run good stuff on the XBOX 360 right out of the box. I'll probably end up going with the 800watt just incase I ever need a decent amount of power.

I looked on the label on the bottom of the laptop, it says 19V -3.4A What would that equate to in Watts? 90 or so?
 
It's actually 65 watts (Watts = Volts x Amps), but that's just the laptop's requirement. To size an inverter for it you need to use the INPUT rating, because that's the actual load it's putting on the inverter. For a 19 volt 65 watt power supply I'd guess it's going to say 120v at about 1.5A, which is 180 watts. Double that for your second passenger's laptop and you have 360 watts. Double that for your "x factor" and you would need a minimum of 720 watts. The 800 would be just fine for you.
 
I ordered the Cobra 800watt inverter from Newegg this evening. Should be here this weekend and I'll try to get it installed and directly wired to the battery. I really appreciate the help and advice guys!
 
@ DR - from what I'm gathering after rereading this thread, is a pure sine wave inverter of no importance to your purchase decision? I sure hate to see you make the same mistake as I did and end up not looking into some of the options that were discussed here. Just so we know, what kind of budget are you working with for the inverter purchase? My only concern is the product quality you might wind up with in the end.

I was wanting to keep the inverter less than $100. I could have done more, but didn't really see the need for what I'm going to do. I won't really run any sensitive electronics on it, and will likely never come close to a full load on it. . A laptop, but I read that they tend to work fine with a square wave. Cell phone will be charged via USB hooked to the computer. Camera batteries MAY be charged on it depending how much I shoot in a day. I have a Canon XSI with 2 batteries, and a Canon 7D with 2 batteries. I may be able to make it one just that and charge those in a hotel room. Mainly just needing to keep my laptop going. I'm planning to use a power strip between the inverter and laptop for a little extra protection, and the laptop will be unplugged when starting the vehicle.

I'll only be on the plains this year for maybe 5 days at the most. The rest is chasing locally around NC, SC, and VA. I'll be back out there next year for 2 weeks, and if I need something better I'll have it by then. I think with the information given, I should be fine with the Cobra for now. Hopefully there won't be any problems.
 
I actually posted last night and then noticed you made the leap and purchased the Cobra, so I deleted my post thinking it was a moot point. I sure hope it works out for you and it seems the model you ordered works for other chasers who chimed in here. If you ever end up going another direction, I can't say enough good things about the high end products that Lind sells per my earlier post. Another person mentioned the AIMS brand (Joshua's post #23 and my post #21), which are also very well built but rather expensive when it gets right down to it. I think for your needs you'll be just fine with the Cobra and I wish you the best of luck this coming chase season.
 
I have an old Vector 300 watt inverter that has served me well for over 5 years, but I only use it during chase season. I am power inverter challenged and want to thank everyone who has contributed to this thread! The experience and ideas are invaluable. Thanks everyone!
 
Got the inverter the other day. Gonna try to get it installed this weekend. What size wire would be good to run from battery to inverter? Was thinking about buying a couples 8-10' lengths from Lowes to wire it to the battery. Gonna put a fuse on it near the battery also, read only that 80A fuse is good. Thoughts?
 
Depending on the wire length, you would need at least #6, preferably #4 wire. The 80A fuse is correct for #4, #6 would need a 70A fuse. Fully loaded, an 800w inverter is going to be pulling approximately 67 amps, which would be ok on #6. If the wire length will be more than about 6 feet from battery to inverter, you want to go up a size (to #4) to compensate for voltage drop.

Do NOT use wire from Lowes, as it will be stiff residential copper, not designed to withstand the constant vibration it will be subjected to in a car. You want to use automotive grade wire, which has a much higher strand count which makes it more flexible and less likely to suffer from vibration damage. You can get this at any autosound store, or even Walmart carries it IIRC.

You want your ground (negative) to be as short as possible. Most recommendations say 12 inches or less, to a solid body bolt, such as a seatbelt or seat mount using a properly sized ring terminal. Make sure you sand down the ground point to bare metal for a good connection. DO NOT run it all the way back to the battery.

VERY IMPORTANT, the fuse MUST be in the engine compartment, no more than 18 cable inches from the battery terminal. You do not want ANY unfused wire (especially high current wire) inside the passenger compartment, because it will burn your car down. If you have any doubts, ask Jason. He knows firsthand.
 
Last edited by a moderator:
I never knew this was going to end up being such a hassle. Can't find hardly ANYTHING I need to do this. Read what you said about not using wire from a home improvement store, but after checking 6 places today....that was my only option. Bought a long length of 4Ga wire to use. Decent looking stuff, thick insulation, stranded, heavy, feels fairly flexible, etc. Something like $1.38 a foot. Can't find a fuse holder over 50A anywhere. Found 80A fuses at auto parts stores, but no holders. Checked 3 auto part stores, a radio shack, 2 car stereo places, and called Best Buy. Can't find the end connectors either that fit 4Ga wire to hook to the battery or the inverter.
BTW, what kind of fuse would you recommend? Glass tube or the flat plug in type?

Was needing this done this weekend, planning on heading West Monday morning. Worse come to worse I'll just go with a $30 cheapo inverter to get me by a couple days.
 
In theory he is correct on the fuse but in the real world (at least for me) I use a 25 amp fuse and it has never blown. I run a 17" inch laptop, phone, camcorder, and a powered 50 watt sub all the time. I have even had multiple laptops going. Kinda hard to believe but I've had 8-1400 watt amps for my subs and approximately 2000 watts going to mids and hi's and was using a 250 amp fuse. And I'm talking about thousand dollar amplifiers, not pyramid. A lot depends on the wire. Too small and you will definitely have problems.
 
Fuse holders don't go by ratings per se, their ratings are dictated by the size wire it takes. You need one that takes #4 in and out, and you can put an 80A fuse in it. I can't believe two car stereo places wouldn't point that out to you. I also can't believe they wouldn't have 4ga wire or the terminals for it. That's a standard size for amp installation. Best buy I would expect to say that over the phone because they're morons, but they should have them too.

There is type AGU (which is an overgrown glass tube fuse), MAXI (which is a huge ATC blade fuse), ANL, which is a 'bolt on' fuse, and AFS, which is a smaller version of ANL. My preference is ANL/AFS, because they are less likely to develop a loose connection, but any one of them will do fine.

I'm serious, don't use that wire from Lowes. Return it if you can, because it's a fire hazard in a car. Automotive wire is floppy like rope. Residential wire is only designed to be flexed a few times during installation and that's it.
 
I use Red/Black Zip Cord and the associated powerpoles from these guys:
http://www.powerwerx.com/wire-cable/red-black-zip-cord.html

I use 4g AGU Stinger brand fuses between my 1st battery, the Hellroaring isolator and the 2nd battery just to be on the extra safe side.

I ran 12g Zip Cord from the 2nd battery about 12 inches and then terminate into two ATC/blade fuses. Then more 12g Zip Cord into the cab.

http://www.powerwerx.com/fuse-holders-fuses/atc-inline-fuse-holders-powerpoles-12-gauge.html

The ZipCord goes into a Rigrunner 4005 for distribution to the rest of the gear.

You can get a Rigrunner 4005 starter kit for about $100 and comes with everything you need for a basic install. Only gotcha, is you need to terminate all your power wires into PowerPoles...but once you go PowerPole...you won't go back :)

http://www.powerwerx.com/west-mountain-radio/rigrunner-4005-starter-kit.html

They even have a Rigrunner 4004 USB kit that comes with 2 USB ports for charging. Wish they had that back when I bought mine!

-Tyler
 
Hate to perform a thread resurrection here, but this looked like the most recent topic covering my question...

After years running inverters through the cig outlet, I've had enough of the warning alarms, blown fuses, etc. and am finally committed to getting the long-overdue hardwiring job done ASAP. I'm rather surprised how little useful instructional information Google spits out on this topic, and found some of these ST threads to be the most useful material anywhere.

At the moment, my Amazon shopping cart contains the following:

Cobra CPI-A4000BC 4-AWG Heavy-Duty AC Power Inverter Cable Kit

Scosche EWFH Single ANL Fuse Holder

My plan is to run the 4AWG wire directly from the battery to inverter, with the inline fuse located right next to the battery, as described in earlier posts.

Now, you'll have to pardon my ignorance with all things car-electrical, but:

1. What fuse best suits my application? The inverter is 400 W, so I would assume something around (400 W / 12 V) = 33 A is appropriate. However, I believe I saw a couple people warn that anything over 20 A is asking for a fire; conversely, it seems almost all the ANL fuses on Amazon and even inverter sites are more like 150-200 A! I doubt I ever need to pull more than 150 W from my setup (usually just a laptop and cell amp), so I'm fine with the most conservative fuse (20 A?) that won't blow if it minimizes safety hazards. Any advice from direct experience would be great here.

2. Where can I pick up a cheap 6" or 12" length of red 4AWG (with battery terminal connectors) to connect the battery to the fuse holder? I'm already a bit surprised at the cost of wire in general, and would like to avoid another $20+ on that, if possible.
 
Back
Top