Inverter shuts down...need some help

**Moby** · 07-30-2005, 04:40 AM

Hello.
My carputer is 99% finished, all the modeling and stuff is done, the pc is in the rear (and don't misunderstand this).
Everything works fine for more or less 10 mins but after this period the inverter shuts down.

My setup includes:
1x300W (600W peak) inverter

Pentium 4 system with 2 hdd ata133 (big ones), 2 cooling fans (cpu & hdd), 1 wifi pci adapter, 1 tvfm card, 512mb ram, 1dvd-rom (notebook) on USB and also the lilliput is powered by the pc-PSU which is a 300W psu.

I tried switching it on again after 10 minutes or so had passed and this time it lasted 3 minutes or so before shutting down again.
I assume the shutdown occurs because the battery voltage goes too low; the inverter has a circuit protection that senses the battery voltage and turns off when it gets below 10v avoiding me to have to walk a long distance

.

What can I do to fix this?
Would moving to a Pentium 3, only 1hdd, no pci cards solve the problem?
Should i change alternator? If so how much does that cost (more or less)?

My car is a vauxhall calibra 2000 16v with a 70Ah battery (which i hoped would hold such power-hunger) and the inverter is directly hooked to the battery with big cables (had to drill holes in my car argh!) - keep in mind that my car also powers my head unit which is a pioneer deh-p5100R (45Wx4)

Please give us some idea!!
-M

**mushrew0** · 07-30-2005, 05:30 AM

try a higher powered inverter, i thought a 300 watt inverter would work for a 300 watt PSU like you but after reading around it looks a 300 watt PSU actually draws a lot more but it only outputs 300 watts. my $150 retail (got it for a lot cheaper) monster 300 watt inverter kept dying with my PC but working with everything else...got a refurb Xanex or something 700 watt one at Fry's instead and its working great!

**Moby** · 07-30-2005, 05:40 AM

humm... i think it is shutting down because the alternator can't provider the power, so increasing the power drainage wouldn't benefit it in any way...

**MatrixPC** · 07-30-2005, 06:21 PM

Inverter overheat protection shutdown????
When it shutdown, did you check how hot it is?
Some inverter will beep if low voltage is detect or overheated.

**Moby** · 07-30-2005, 08:24 PM

tested, its just mildly warm.

**techy101** · 07-31-2005, 06:24 AM

The inverter is most likely to small. I highly doubt that your alternator isn't putting out enough current. If you figure 60% efficency in the inverter it is still only pulling at max 35 amps. Which should be within what your alternator can generate, unless it's a classic VW Bus or something. Also, the inverter won't draw directly from the alternator, it will pull any extra power that it needs that the alternator can't generate from the battery until the battery is depleted to the point that it's on par with the alternator.

Try a larger inverter. As your PSU is heating up, it starts to suck more power. Thats probably what is happening. It's pulling more than 300 watts because it's not 100% effecient. Thus your inverter going into protect mode.

Hope this solves your problems.

**numbers** · 08-01-2005, 12:19 AM

Good ideas here. Add to the list the possibility that the 12v power wires going to the inverter may also be overheating and lowering the voltage below the cutoff point.

**Moby** · 08-04-2005, 09:58 AM

thanks for the suggestions, i will try a bigger inverter and then let you know.

**wardemon666** · 08-04-2005, 02:02 PM

Hey,

I have the same problem. My inverter shuts down after about 20-30 mins!

Its not the inverter as I have my computer running off a 75 watt inverter and it works no prob (its hardwired into my car, had it before the carputer), Except for when I come to a stop or if I slow down, it starts to "whine"

I installed a 400 watt inverter through a ghetto relay startup/shutdown controller, and im guessing its that.

I tihnk the relays get "hot" after 20 mins or so, is that possible? Or maybe its a grounding issue? I grounded it in the middle of the car close to my shift stick (there was a screw there, to hold the plastic covering)

Anyways, if anyone could give me some ideas it would be apprechiated

Thanks

**numbers** · 08-04-2005, 05:08 PM

Again, the wires carrying the power to the inverter could be overheating and causing voltage drop due to increased resistance. This includes relays, terminal connectors, anything carrying power. Just measure the voltage at the inverter just before it shuts down, but not after (there will be no voltage drop after it shuts down because almost no current will be flowing) and if it is too low, you probably have wires overheating somewhere.