Thread: CarPC Shopping List

Originally Posted by KRMit

I've been wanting a CarPC for a while now and I'm finally ready to commit to the project. I am however working on a tight budget. Here is what I'm planning to use:
1. DWW-750FM
2. IBM form factor PC (I already own it so no cost)
3. 700w power inverter (given to me)
4. UPS (given to me)

My plan is to hook up the UPS to the power inverter and then plug the PC into the UPS. I want to set the power button on the PC to hibernate. My theory behind this is that I can have the power inverter turn off with the ignition, then all I have to do is press the power button for hibernate. I'm thinking the UPS should supply plenty of power for the PC to remain in hibernate for an extended period of time.

First of all, the UPS units do not like inverters as a general rule. I say this from experience.
Second, hibernation requires no power whatsoever, since it writes the system state to the HDD. For what you're talking about, the UPS isn't necessary.

Am I crazy?

Well, you joined our hobby. I don't know what that means, exactly.

I've heard of people getting engine noise when using an inverter but I'm hoping maybe the UPS will prevent this. I've got 0 experience putting a PC in a vehicle so any help would be greatly appreciated!

Nope. The UPS is likely to add even more noise than just the inverter.
For best results keep power cables as far away from signal cables (audio and video, primarily) as possible. Even that is no guarantee.

Originally Posted by KRMit

No one has any input on this?

No. None at all.

Welcome to our madness!

Do lots of research here. There's lots of information about everything you're talking about, as well as other alternatives, primarily for power. If you're on a really tight budget, then your proposal will do just fine.
Before I bought my DC-DC power supply, I ran my setup from an inverter. It works, but there are some drawbacks, obviously.

Keep us apprised of your progress and feel free to start a worklog with photos and such.

I'm not saying the logic of using the UPS is flawed at all. I wholly understand the reasoning.
The problem isn't with the reasoning, it's simply that UPS units don't like operating off an inverter, for whatever reason.

I believe it has to do with the modified sine wave that the inverter puts out, and it doesn't allow the UPS to charge the battery properly or efficiently. I could be wrong about that, though.

Originally Posted by KRMit

Thanks for the replies!

I think I may ditch the UPS and connect the PC straight to the inverter with a relay switching the inverter on/off. The downside is that I'll have to manually hibernate the PC before I turn the ignition off.

At least this gives me a solid point to start at. I should be able to order the DWW-750FM tomorrow.

try to find a wire on the distribution block that kill the inverter power (like your radio) when ACC off. i did that. then you only need a push switch to start / shut pc. in XP - one push is start, another push is telling xp to shut down correctly.

I know you're operating on a budget...
However, you could automate the startup/shutdown by using a startup/shutdown controller. Basically, it will simulate the pressing of the power butting on an ATX-compliant motherboard. If you set XP up to hibernate, then the simulated button press will send the PC into hibernation or resume from hibernation.
It beats having to press a button every time.