Problems I've had with inverter (Sima 300w - 600w)

**dagnasty** · 01-17-2006, 05:38 PM

I'm not sure if this is directly related to the inverter so don't quote it. It's just some problems (and few solutions) I've come across with my inverter and hopefully, future carpc.

My inverter is a Sima 300w continuos, 600w peak. (or so it advertises)

PC I've been using to test:

A7N8X 2.0 Deluxe motherboard WITH
2 onboard ethernet ports
onboard 1394 port
Onboard 5.1 Audio

Radeon 9800 128mb
20gb IDE 5200rpm (desktop)
PCI wireless card
1 stick of 512mb

5'' inch lcd is not on the inverter.

I first tried with a 140w (cheap) power supply just to see if it'll even carry the load but wouldn't get past POST without overloading the inverter (LED on inverter goes off) I then tried a (cheap) 250w power supply and received the same results. I then threw in a 300w power supply (probably cheap also) and made it past POST and all the way up to the windows login screen and then overloaded the inverter. I assume it's because of the extra power needed to process windows. Now, why would a pc that (I assume) doesn't consume 300 watts overload a 300w continuous power inverter? I didn't spend any money on the setup I used to test the inverter so I'm not too worried about much of anything, I can just grab another less powerful motherboard and it'll probably work.

So, can anyone give me an explanation on why the inverter would overload? Does my setup and motherboard in fact, consume anything near 300 watts?

Has anyone else had any experience with this or any other Sima inverter?

**RawsonDR** · 01-17-2006, 05:52 PM

I don't have any experience with inverters, but I have a couple suggestions.

You may want to attempt to underclock your processor to see if you can get it to squeeze by. Changing the FSB to 100 is a good place to start, and you can subsequently lower the CPU voltage. The min voltage for your board is probably about 1.375.

A weaker graphics card will help out a lot as well. If you don't have one and feel this is worth spending time on, you can underclock your graphics card as well. That will involve saving the video BIOS, modifying it, and then reflashing the card.

I honestly don't think just changing the motherboard is going to improve your power usage dramatically. You should see the greatest difference by underclocking your processor. What processor are you using anyway?

**dagnasty** · 01-17-2006, 05:58 PM

Originally Posted by RawsonDR

I don't have any experience with inverters, but I have a couple suggestions.

You may want to attempt to underclock your processor to see if you can get it to squeeze by. Changing the FSB to 100 is a good place to start, and you can subsequently lower the CPU voltage. The min voltage for your board is probably about 1.375.

A weaker graphics card will help out a lot as well. If you don't have one and feel this is worth spending time on, you can underclock your graphics card as well. That will involve saving the video BIOS, modifying it, and then reflashing the card.

I honestly don't think just changing the motherboard is going to improve your power usage dramatically. You should see the greatest difference by underclocking your processor. What processor are you using anyway?

Athlon XP 2600+

I was actually considering underclocking the processer and possibly the video card. Will it make a drastic difference? if so, how much?

Don't think that moving to a motherboard that doesn't have all those extra compenents will make a difference in power usage? I do.

**DarquePervert** · 01-17-2006, 06:02 PM

I had the same problem trying to test my setup with an inverter.

As I understand it, the inverter needs a certain amount of current form teh batter or alternator to power whatever is plugged into it. If there's not enough current, the inverter 'overloads'. It's not a true overload, but a 'battery fault'.

You may be able to lower the current draw by underclocking the CPU, as RawsonDR suggested.

One other thing...
If the inverter is one that plugs into the cigarette lighter (mine is), that may be the/a source of the problem, as well. Supposedly the cigarette lighter port isn't very efficient in some way. I'm not certain how/why, though. If your inverter is a direct-to-battery type, then that rules this idea out. If not, perhaps a direct-to-battery inverter may be the way to go...

**dagnasty** · 01-18-2006, 02:10 AM

came with cig lighter but wired direct tobattery with 8 gauge.

cig lighter wiring isn't made for high amperage.

**neo__04** · 01-21-2006, 10:13 AM

Hey,

I just setup the same type of thing..
Got a 300w - 600w max inverter
runs like a dream

the pc is only a athlon 700 with xp on it

definately wire it direct to the battery cause the wiring on your
cig lighter will be too small to carry big loads!!

cheers