pc using a lot of power in hibernation?

Dj-[NRG] · 02-20-2007, 02:16 PM

Hi,

I have a problem that started last week...

when i put my pc in hibernation, it's eating a lot of power..
when i shut down my car and hibernate my system, i measured the volts on my battery: 12.81.
aproximatly every 2 seconds that lowered with 0.01 volt...
is this normal? my car had a dead battery this morning, and i think that is the problem...
any idea why i have this problem? it used to work fine before...

Greetz

Dj NRG

DarquePervert · 02-20-2007, 04:23 PM

Your PC shouldn't be drawing ANY power when hibernating. The PC writes all the contents fo RAM to a file on the hard drive and shuts off.

Are you possibly referring to standby mode? That's where the PC writes system state to RAM. That will draw power, as the PC requires the RAM to be powered to maintain the system state.

Where is it drawing the voltage? Is that between the PSU and the battery or between the PC and the PSU? Also, is it on the ACC line or on the 12v hot?

Dj-[NRG] · 02-20-2007, 11:12 PM

I was idd reffering to standby... sorry for that.
for now i'm only sure it draws power from my battery... shutting down the pc completely and pulling out the fuse helpt for that. will test this afternoon where it exactly draws power. what do you mean with the acc? that's my remote for my psu, right?
what does a pc normally use when put in standby?

Greetz

Dj NRG

yaohui · 02-21-2007, 06:23 AM

Why not check you DC-DC Regulator? Maybe it has some problem!

DarquePervert · 02-21-2007, 07:14 AM

A PC will draw power while in standby. Power is required to keep the system state stored in RAM. That's how standby works.

A PS will not draw power in hibernate. System state is stored to a file on the hard drive and powered down.

Now, Standby is, by far, the fastest method of shut down and/or startup, but you pay the penalty of the power draw. Normally, PC standby shouldn't draw enough to drain your battery overnight.

Is the PSU shutting down 5v USB devices?

Could there be anything that's happening that might bring the PC out of standby like Wake on LAN (if it can connect to a WiFi network, for example)?

If there's nothing that you can determine that could be causing the increased load, then the battery could be incapable of holding a full or near-full charge.
You could also have an alternator that doesn't put out enough to keep the battery charged.
You may also not drive enough to fully charge the battery. If you only drove a couple miles to work each day, this could be the case.

To help troubleshoot, wiring diagrams and specs would be helpful.

Dj-[NRG] · 02-21-2007, 11:55 AM

Hi, allready thx for the answers.

wiring diagram is here
the problem seems to be solved today... will check my battery later today.
alternator is only 3 months old (110Ah, the old one was only 70Ah) and my battery is also only 3 months, so i doubt that wass be the problem...
anyway, my usb devices stay powered, but i do not think they draw a lot of power... (steering wheel controls are not powered via the pc, radio is not connected at this time, touch screen is shut down)

If the problem comes back I'll let you know...

Greetz

Dj NRG

Fuse · 02-21-2007, 11:14 PM

Quote: Originally Posted by Dj-[NRG]

Hi,
when i put my pc in hibernation, it's eating a lot of power..
when i shut down my car and hibernate my system, i measured the volts on my battery: 12.81.
aproximatly every 2 seconds that lowered with 0.01 volt...
is this normal? my car had a dead battery this morning, and i think that is the problem...
Dj NRG

To see if the PC, or anything else, is using power you need to check for current flowing out of the battery, not the battery voltage.

turbocad6 · 02-21-2007, 11:43 PM

^^^ he's right, you need to check the amperage draw of the system while off-standby... this is a much more relible indicator of what your dealing with, voltage drop-time isn't very useful in calculating anything really..

ZtH01 · 02-21-2007, 11:50 PM

Quote: Originally Posted by Dj-[NRG]

Hi, allready thx for the answers.

wiring diagram is here
the problem seems to be solved today... will check my battery later today.
alternator is only 3 months old (110Ah, the old one was only 70Ah) and my battery is also only 3 months, so i doubt that wass be the problem...
anyway, my usb devices stay powered, but i do not think they draw a lot of power... (steering wheel controls are not powered via the pc, radio is not connected at this time, touch screen is shut down)

If the problem comes back I'll let you know...

Greetz

Dj NRG

Alternators are not rated in Ah, it's straight amps. Anyways, rewound alts typically put out LESS power at lower speeds. Most cars require a smaller pulley, and thus a shorter belt to make enough power to charge the battery at idle. It may be a combination of the rewound alt not putting out enough power, and, assuming you live some were cold, the cold weather effecting the battery. Or perhaps the alt just plain isn't getting a chance to charge the battery. Or, the alt could be defective. My previous alt last a whole 6 months, it was only putting out like 30A at idle, so the battery would never fully chage... Could be a bad battery too, or both.

Bad batteries tend to kill alternators, and bad alternators tend to kill batteries. It's a viscious cycle. Get em tested, most parts stores will do it for free.

Dj-[NRG] · 02-22-2007, 12:29 PM

I'm sure it's not a problem with my battery or alternator (got the fuse out and all the problems were solved)...
anyway, will not use my pc for a while, since my screen died...
have to send it back to hongkong, so that will take a couple of weeks probably...

Greetz

Dj NRG

Borte · 02-22-2007, 01:58 PM

Quote: Originally Posted by DarquePervert

A PS will not draw power in hibernate. System state is stored to a file on the hard drive and powered down.

The PC can indeed draw power in hibernate, my laptop in my car will drain it's battery in about 8 hours while it's hibernated.

I know that there's even software that will wake the computer from hibernation so the computer is not completely off in the hibernation (S4 state). Check this link from more info http://www.vbforums.com/showthread.php?t=396217

I got this from the web (http://findarticles.com/p/articles/m.../ai_n9462564):

Quote:

Hibernation takes the contents of the DRAM and writes it directly to a special file on disk. It then proceeds to shut the entire system down, including the DRAM. Upon resume, the system reads the contents of hibernation file and places it back into memory. Resume is not quite as fast as stand-by, but hibernation uses less power and is less prone to failure if the power goes out. In hibernation, the system appears to the user to be completely powered off.

So it will be able to live longer on the battery in S4 (hibernation) but it will not last forever...

Just my two cents....

Cheers
Borte

evandude · 02-22-2007, 03:00 PM

Quote: Originally Posted by Borte

So it will be able to live longer on the battery in S4 (hibernation) but it will not last forever...

One important distinction here is that if you cut power while it's in standby, it won't resume, and will need to do a regular boot instead. If you cut power while it's in hibernate, it will resume just fine. The computer may still draw power during hibernate (keeping certain minimal peripherals active, or whatever), but it's not REQUIRED to in order to resume properly, unlike standby. If you're putting your computer into hibernate, it's probably a good idea to use a power supply/SDC setup that simply completely cuts power after you hibernate.

Now, if you're relying on advanced power functions on the mobo like having it power back up after a certain period of time or something like that, then cutting power during hibernation would be a different story, but I don't think that's usually the case.

Sonicxtacy02 · 02-22-2007, 03:06 PM

This has been a debate i feel i've proven over the course of owning a carPC. Fact is hibernation takes NO power. I put an old system in hibernation for about 2 months, taking the pc outta one car and putting it into another. The PC resumed just fine.

Borte · 02-22-2007, 03:07 PM

Quote: Originally Posted by evandude

One important distinction here is that if you cut power while it's in standby, it won't resume, and will need to do a regular boot instead. If you cut power while it's in hibernate, it will resume just fine. The computer may still draw power during hibernate (keeping certain minimal peripherals active, or whatever), but it's not REQUIRED to in order to resume properly, unlike standby. If you're putting your computer into hibernate, it's probably a good idea to use a power supply/SDC setup that simply completely cuts power after you hibernate.

This is true but cutting the supply on a laptop would make it run of the battery (even in hibernation) causing it to drain the battery.

I have this setup in my car, cutting the supply when I turn of the ignition (the computer auto hibernates after 10mins). My problem however is that I need the laptop battery to boot the laptop so draining my battery is not a good solution...

Edit: Sonicxtacy02 posted while I was typing, I agree that you can resume with out problems, but it will still drain the laptop battery (and still resume properly when running on supply).

cheers
Borte

DarquePervert · 02-22-2007, 03:57 PM

Quote: Originally Posted by evandude

One important distinction here is that if you cut power while it's in standby, it won't resume, and will need to do a regular boot instead. If you cut power while it's in hibernate, it will resume just fine. The computer may still draw power during hibernate (keeping certain minimal peripherals active, or whatever), but it's not REQUIRED to in order to resume properly, unlike standby. If you're putting your computer into hibernate, it's probably a good idea to use a power supply/SDC setup that simply completely cuts power after you hibernate.

Now, if you're relying on advanced power functions on the mobo like having it power back up after a certain period of time or something like that, then cutting power during hibernation would be a different story, but I don't think that's usually the case.

True. Actually, it's not the PC maintainiing power to devices, it's the PSU. It's providing 5v to power USB devices that require it, basically. ANd yes, that will drain your battery, without a doubt.
I hibernate in my truck and the PSU w/ SSDC will cut all power after a certain amount of time after simulating the press of the power button to put the PC into hibernation.

You can completely cut power to the PC once it's in hibernated and disconnect it from anything and everything and leave it disconnected. Plug it in and press the power button

Quote: Originally Posted by Sonicxtacy02

This has been a debate i feel i've proven over the course of owning a carPC. Fact is hibernation takes NO power. I put an old system in hibernation for about 2 months, taking the pc outta one car and putting it into another. The PC resumed just fine.

You, sir, are correct.