Any electricians? (car electronics...)

[Thaco]

hey, i'm looking to install a 1000W inverter in my car, it says in the manual to use 2AWg wire, but that is HUGE, is it really necessary? could i double up on 6 or 8 gauge for the same result?

also it says "never have a length more than 5 feet" is this really firm as well? i want to install the inverter under the passengers seat, i'd love to install it in the engine area, but there's just zero room, and i'd be concerned about moisture.

[hellraiser456]

yes that wire would be necessary...if you had to go over five feet...i am sure you could do it with even bigger wire. 8 or 6 gauge i believe would be far too small. you could double it up i suppose...but i would just invest in one easy run.

as for putting it under the seat i don't know if that is a good idea ethier. the inverters need cooling and under the seat doesn't get a lot of air flow.

also i would look into seeing if you can find a bigger alternator if you plan on using that kind of inverter, and a battery as well if you plan on using it while the car is off.

i feel i should ask...why do you need a 1000 watt inverter?? you sure you can't go with something smaller? the 1000watt ones last time i saw them are huge. i powered a small CRT tv and a n64 of a 150 with out any problems...and that should run most laptops and the like with ease...and will be a hell of a lot easier on your charging system. hell you can plug that into your cigarette lighter socket.

[Thaco]

i would like to go smaller, but i have a 400 in my current car and it has a button power instead of a physical switch, which is terrible, also it doesn't have mounting holes, which i need... maybe I'll go for the 300W instead, most likely the most I'll ever power is a couple of laptops and a phone charger or 2.

for a 300W what kind of wire would i need? i really would rather it in the engine bay, but as i said, I'm concerned about moisture, and there isn't much space up there as it is, also it'll probably auto shutdown then i start the car as itt get's too low of voltage... and then i'd have to pop the hood to reset it.

[Mazstyle]

1000w! :eek: What do you plan on running? a cappuccino machine??

[Zero102]

1000W output probably is close to 1500W input, so 1500W/12V = well over 100A. Yes, #2 wire IS necessary (IIRC the voltage drop at 100A is something like 0.01V/foot), but yes, you can also go more than 5 feet on #2. For lengths within the car #2 wire would be fine for that inverter, you may get some small voltage drops but as long as it is above 12V when it reaches the inverter you're set. You wouldn't be running it at full power with the ignition off for long (or your battery would die) so you don't need to worry much about it's operation with only 12V supply. If you are grounding to the frame of the vehicle make sure you upgrade the engine grounds and the ground cable for your battery. The electricity needs to make a full loop and so many people forget this little bit.
Also check the rated output of your alternator, if you run a sustained load of 1000W on the inverter that is likely equal to or greater than the maximum output of your alternator. (Nobody ever just uses an inverter for what they planned, so I thought I should say that)

Mounting it under the passenger seat may or may not be a good idea. A 1000W inverter will make quite a bit of heat and it may not be properly ventilated under there (although most of them have fans, it will probably get full of dirt and dust under there).

Depending on what brand of laptops they are a 300W probably won't be enough power. I have a 400W inverter in my car and my friend has one of the Dell XPS gaming laptops, he can charge it with the power off, but if he turns on the laptop it kicks my inverter off. Most laptop adapters are rated in the neighborhood of 90-110W, but make sure you check yours before picking your inverter.

To get the wire size you first need to know the current draw. For inverters add 50% to the output power, then divide by 12V. There are lots of wire sizing guides, but basically you need to figure out the voltage drop along your desired length of wire. More than 0.1 or 0.2V and you need to up the wire size. Add up the length of all of the wire to complete the circuit (i.e. positive and negative) to calculate the full voltage drop.

[Thaco]

Thanks for the info guys, i didn't really want or need a 1000w but that's the only one i could find with a physical on/off switch, and that's mountable... i wanted more like 5-600, Canadian tire does have one that's 300w, and i have a 175W cig lighter one, so maybe i'll just dot he 300w and have the other for backup... the 300w isn't mountable, but it does have the physical switch, i'll see if i can find some place under the hood for it, and see if i can rig up some plastic cover to keep the weather out while still allowing ventalation.