Thread: power and inverter with a M2-atx

I'm pretty sure your logic is flawed, and that the problem lies with your alternator/battery, but I'll let one of the electrical gurus analyze this..

If I was you, I will try to work around using the M2 to power the Compaq. Why don't you go that route? Does the Evo has special PSU/connector like those in Dell?
You don't want to do Car power -> regulated DC - > Inverter -> AC-DC.
Another problem is that the M2 only has 8A ( I think) on the 12V rail which is about 100W.

Yeah, as matrixPC pointed out, it would not be a good idea because you would only be using the 12v output, which is a bit under 100W. Not to mention, a 175 watt inverter can supply 175W, but it will take more power to run it at full load than that because it's not 100% efficient. As a rough guess, if it's 85% efficient that means it would draw over 200W of power when it is supplying 175W output, and worse if the efficiency is lower than that. So you're probably looking at about DOUBLE the power on the 12v rail that the M2-ATX could supply.

There are dedicated, single-output +12v DC-DC power supplies out there, however I don't know of any that are larger than about 100W, so that is probably not a good solution either.

In my opinion, your best bet is to figure out the wiring of your computer so you can hook up the M2-ATX directly and eliminate the inverter.
If you aren't electrically inclined enough for that, then perhaps you should buy a better inverter that can deal with lower input voltage. I have a coleman powermate 400W inverter that can survive crank with the computer running, and I only paid about $25-30 for it. and if it can survive crank, it should certainly be able to keep running while the engine is running, even at low idle. It sounds like you are running a relatively power-hungry PC; with a 175W inverter, you may be pushing it close to its rated limit, which means it will be strained more when the battery voltage droops than it would be if it was only running at, say, 50% load. That's one possible advantage of using a larger inverter, such as 400W. Just make sure you search the forums for recommendations of brands/models, because some inverters handle low input voltage better than others ( you want to find one that can survive engine cranking, ideally )

One question about a POSSIBLE fix to your current problem: do you have GOOD power wiring to the inverter? Bad=existing wire in the dash, or a cigarette lighter plug... Good= a suitable-gauge power wire run directly from the battery, and a solid ground to the chassis close to the inverter.
If your power wiring to the inverter is poor, there will be extra voltage drop on them, which would cause the inverter to get a lower input voltage than the actual battery voltage, which could make it shut down when the battery voltage had only drooped a little bit. One check would be to measure the battery voltage with the car idling and see at what voltage the computer shuts down, and then repeat the process by measuring the voltage at the power terminals of the inverter, and see if the voltage is much lower. If it is, then you should check/improve your wiring.

Originally Posted by Lava

I purchased this off of ebay last week.

http://cgi.ebay.com/Aims-400-1200-Wa...QQcmdZViewItem

It should be here today but for some reason i think i may run into the same problem with that inverter. but maybe not

I'll let you know

With 10V minimum working voltage, it may or may not survive cranking, but I am sure it will survive at engine idle.
If this inverter still give you problem, you may have to check wiring and voltage at the inverter and battery while engine is idle.
I used a 400W Xantrex inverter before in the Supra and it survive engine cranking without any problem.

adding a ps in front of an inverter etc isnt going to do much for you(gonna do nothing but be wrong). if theres not enough power theres not enough power. plain and simple.

buy a nice sized cap(it stores energy), put your system after the cap.. then when you hit hard when your car is at idle(not putting alot of juice back in the system). it will drian the cap before your battery.



Matrix he did say at idle with the music loud. im guessing otherwise when hes moving the alternator can keep up.. its just when hes stopped. what else does your system consit of? im guessing amp and sub/s?