The first power related problem occured in less than a couple of weeks. I didn't know a whole lot about inverters so I just bought what I thought was a reasonbly priced (under $80) 900watt "no name" inverter. Well I guess you get what you pay for.... it failed in spectacular fashion with smoke pouring out of it.
I was a little more carefull with my next inverter purchase....Schumacher Electric Corp. has been around for years and has built a good name for itself with their line of battery chargers....so I purchased a 750 watt inverter for about the same price as the original inverter.
Eveything worked fine for about the next 8 months or so then problems started again.....the low battery alarm on the inverter started going off every time I fired the system up and the car starter seemed a little slugish. All this pointed to a failing battery and since it was a couple of years old and the original battery that didn't seem to far fetched. I didn't jack around when it came to a new battery....I replaced it with a "red top Optima" 910 cranking amps/780 cold cranking amps....this battery has balls.
The low battery alarm problem went away.....for about a week....then it started again and a few days later the inverter just wouldn't fire up at all. Another dead inverter....two in less than a year.
Now I was getting pissed....was there nobody on the planet capable of making a dependable inverter? I started doing a lot of research, first I contacted every manufacatures rep I new that had an inverter line and had them send me all the information they had on the lines including the spec sheets. I also down loaded the spec sheets for the two inverters that had already failed.
Then I went to several high end automotive audio/video installers and got their input on the subject. In the end I knew more about inverters than I ever wanted to know.
There were a few things that stood out about the inverters I had purchased and about 90% of the other inverters available:
1) They required 12.7volts DC input to output a full 120volts AC....There isn't a 12volt car battery on the planet that can do that unless the car is running and getting charged by the alternator in which case it will have around 13volts output.
2) They were inefficient in their function of coverting 12v DC to 120v AC
3) They would shut down if the DC voltage dropped below 12v
I have a term for this.....they sucked
After all this research I bit the bullet and bought a nearly $200 1000watt Vector Research inverter....this Inverter is very efficient, draws very little voltage at idle, can output a full 120volts AC with only 10.5volts DC input and will not shut down unless the voltage drops below 10volts DC.....But they are very insistent on how the inverter is connected. Depending on the distance from the battery they absolutly insist that you use the correct size cables (which for 15 feet was a minimum of 4guage).....now I was already using a 4guage cable for the hot side but I was just connecting the Ground to the car chassis. As it turns out that doesn't work very well.
To test what I had setup I first checked the voltage across the battery....12.5 volts....then I checked the voltage at the inverter location.... 11.4 volts....not good. I then connected one lead of the meter to the ground side of the battery and the other to the hot side at the inverter location....12.5 volts....so the 4guage cable was doing it's job....next I connected one lead of the meter to the hot side of the battery and the other to the ground at the inverter location....11.4 volts...."Huston I think we have a problem"
Taking some of the advice I got from the audio installer shops I scrubed all of the ground connection points down to bare metal and ran the test again....12.1volts....better but not there yet....so I dug up an old gold plated battery connector that I had laying around that just happened to have two additional connectors for 8guage cables.....I added these additional cables and connected them to the chassis, reran the test and....12.5 volts....about time!
Then I installed the new inverter
Problem solved right?.....WRONG. Everything worked perfect for about a day then the pc refused to power up at all.....there were only a few possibilities here....either the inverter died.....again.....the PC died or the psu died. Well I was at wits end....and if the inverter died I was going to go ballistic so that was the first thing I checked. Since I was already pissed beyond discription I turned the inverter on did not start the car and plugged a 10" Circular saw into it to see if it was working....the saw fired right up and I proceeded to cut about 10 or 12 chunks off of a pressure treated 4x4....still not convinced I pluged my 5 horsepower air compressor into it (which also fired right up) and while it was still running I cut off about 5 more chunks of the 4x4 with my circular saw. At this point I started to cool down...at least a little bit.....because the problem was obviously not the battery or the inverter.
I turned my attention to the PSU at this point and after jury rigging a spare PSU to the pc it fired right up.
Now there is a good side to this and a bad side.....I knew I was taking a chance when I used a small form factor psu but it was able to fit in the system with no modifications.....unfortunatley it also died....probably because of the excessive heat generated in a car.
So this time I modded a full sized 380watt psu to do the job....what a ###### that was!
In order to change out the PSU the entire pc has to be pulled out of the car....what a pain....the other pic below shows the difference in size of PSU's....the white line shows the maximum size that will fit.
As you can see a lot of modifications needed to be done.....the heat sink are too high, the power cable plug has to be relocated and most of the psu case just has to be removed.
Here's another view
There were other mods that needed to be done as well.....the 20pin atx connector had to be converted to a 24 pin atx and I also needed to add a SATA connector for a Hardrive upgrade that I decided to do while it was apart.
Here's the finished modded PSU attached to the bottom of the PC frame
I knew that heat was going to be a problem with the reduced heatsink size, so if you look real hard you can see a fan installed to blow air over the PSU.....there will also be an exhaust fan on the other side (shown in another pic) sort of a push pull arrangement
Another pic fully assembled in it's upright position
I also made a couple more ugrades while it was apart.....the hard drive was ugraded to a Seagate 500gb Perpendicular drive and Since I had a Turion 64 with a 1mb cache lying around from my old office rig, I installed that too.
It took a little modification to the heat sink to make it work (It hit the mounting bracket before it made contact with the cpu) but a little whacking on the mill and a piece of plexiglass to make up the difference for the loss of a heat spreader cured the problem
After all of this I put it all back together and the last mod was the exhaust fan for the psu
It's been several weeks now and no new problems have cropped up.....in fact it works perfect (fingers are defininatly crossed).
I guess the morel to the story is that you can't overlook anything. One kink in the armor can bring the entire system crashing down.
Hopefully this will help some of the more adventurous of you out there if you decide to put together a system like this.....just for the record it does kick the crap out of a standard head unit.
On the other hand my annual birthday BBQ which has turned into a full fledged family reunion with an attendance of over thirty and people flying in from all over the USA turned out pretty good.
) but in the USA a football isn't round and we'd rather get knee walking drunk and then run over each other with our cars after the game 
