Safe to put thinkpad in laptop bag in sleep mode?

I have a T400 and when the laptop is in sleep mode (not hybrid sleep) I can still feel a little bit of heat coming out the left side vent. Because of this I sometimes keep the zipper open on my top loading bag. Is it safe to put this laptop fully sealed in a bag when in sleep mode and what is producing the heat while sleeping?

 

I'm sure that you'll be just fine, just as long as you keep it open a little and maybe the vent side as close to the opening as you can, should be OK.

 

Yes, it's OK. I do it all the time and it doesn't need to ventilate.

Cheers

 

If the fan isn't shutting off after a couple of seconds when put to sleep, that may be a problem. I would update drivers, etc.
If the fan isn't shutting off, I would put it into hibernate or shutdown before putting it in a tight case. Something like a backpack might be okay, but definitely not a sleeve.

 

Yeah, the fan shouldnt be running when in sleep. Make sure the laptop is actually in sleep or isnt waking up in your bag for some reason. Also, if you unplug any devices when the laptop is in sleep it will wake up, so check on those things because I usually transport my laptops in sleep mode and as long as they are properly sleeping there wont be any problems carrying them in a bag.

 

So I'm not sure if the fan is on or if the heatsinks near the vents are just giving off ambient heat from keeping the ram powered. I don't hear any mechanical sounds.

The problem I am running into is my laptop didn't wake up from sleep. I took it out of the sleeve and the cresent moon light was on but I hit power and nothing happened also Fn+F4 doesn't do anything. If I just put it to sleep and resume a few seconds later that works fine. Not sure if the failure to wake is actually a issue separate from heat.

 

i carry mine in the bag all the time in sleep mode. no fires so far.

 

That's what sleep mode was meant for. Problems only arise when the computer gets stuck in the "trying to go to sleep" mode (insomnia perhaps?) where the processor is still going hot and the fans are running. If the fans are running, the computer needs circulation.

If you can't hear the fans: they're off and so is your processor. You can easily hear the fans on the quietest laptops if you put your ear up to them. If there's just some heat coming from your vents, that's just ambient heat, like you said, and is perfectly okay to pack up.

 

The T400 should be almost as cool sleeping as when shut off. Definitely no spinning fan, in fact no spinning nothing. There is minimal voltage applied to RAM to keep its contents, other than that the "crescent moon" LED should be lit (NOT blinking).

I don't ever shut off my T43 neither did I shut off my T61. Both sleep silently, you can carry them around in whatever you like. They emit something like 0.2-0.5W of heat probably and that can escape through the chassis even if all air vents are obstructed.

If your laptop emits noticeable heat but appears to be sleeping, you have to remember that the responsible body for the sleeping function is your Operating System (NOT BIOS!!!) and it may have failed to properly shut down all devices prior to sleeping. Happens all the time to many people.

What you can do is charge the battery, and leave the machine sleeping on the table. It should survive at least 24 hours sleeping, probably much longer. If the battery drains in less time, most definitely something is not shut down and drains your battery and subsequently emits heat.

 

the only time i've had my laptops get stuck in "insomnia" mode was on days when windows automatically downloaded some updates. It is really quiet obnoxious.

 

I use Ubuntu 9.04 on my T400. I hope it is ok to carry the computer in a bag in sleep-mode. The crescent indicator is on while its in sleep mode and I have carried it this way for more than 12 hours. I guess it means that the sleep mode was working fine. When I open the case after carrying it in sleep mode, without me pressing the sleep button, it shows me the login screen again.

Are these behaviors fine? Or is it not OK to carry it in sleep mode while running Linux?

Thanks,
Bibek

 

Sounds like you enable sleep when lid close. So then when the lid is opened again, the computer resume from sleep. Try to find that option in Ubuntu and disable it. Then it will stay asleep even though you open the lid afterward.

 

If you want to really know how well it sleeps, you need to clock the wattage. It is relatively simple to do. Next time you are about to put your T400 to sleep, check the battery readings, namely the one that reads out how much watt-hours the battery has left. Write it down, and after hopefully long sleep (the longer, the more accurate you can calculate), check the reading again right after wakeup. Subtract the first reading from the last, which will give you how much watt-hours the battery was drained for during sleep. Divide that different by amount of hours of sleep (with minutes too!) - f.e. 2.5 for 2 hours 30 minutes. The resulting figure will be a relatively accurate average watt power consumption. It should be a much lower figure than the average power consumption of a modern laptop when active-idle (desktop). T400 idles at about 6 to 12W, depending on configuration, software loaded, etc. A sleeping T400 should draw about around 1 watt on average, a much lower figure than any "idling" as you can see.

You should definitely post your results, so internet public can benefit from comparing their readings to yours

 

How do I do this?

 

This is not enabled. The laptop doesn't sleep when I close the lid. It sleeps after I press Fn+F4. I close the lid and carry my computer around and when I open the lid to use it, the computer wakes up. I looked for power management options in Ubuntu 9.04 to fix this, but couldnt figure out how.

Bibek

 

I suggest you to install the excellent BatteryBar software.
To go back to the topic, I carry my T61 everyday in sleep mode (it sleeps overnight) without a single problem. I however notice that the case is a little bit warm, but I guess it's because of the memory, which needs to stay powered up. And anyway, the crescent indicator is on, meaning that toggling to the sleep mode succeeded.

 

Even I've keep my T400 on sleep for long hours and there've been no problems so far. but i wanted to ask the community here to make sure that everything is running OK since the computer wakes up as soon as i open the lid.

Btw, is BatteryBar also available for Linux? I don't have Windows.

And, surprisingly (and causing some worry), the battery power indicator on my laptop used to show 4 hours 40 minutes when 100% charged, a few days back. But suddenly, these days, it shows 2 hours 20 minutes when 100% charged. No change even after turning off wireless, bluetooth etc. What just happened to my computer?

Thanks,
Bibek

 

Well I'd say that the computer correctly entered into sleep as long as the crescent indicator is on.
Sorry, this BatteryBar is only for Windows.

Regarding your battery, I'd say it's a misindication ; your computer cannot suddenly consume twice the power with the same peripherals

 

I hope the same too Just worried if the battery (or some of its functions/parts) broke down

And please let me know if you find some good battery indicator for Linux.

Bibek

 

Quite often, the T400 will not go into sleep mode, or come out of it.

There are many times this happens; you put into sleep mode, and put in your bag, but it's not off and ends up baking in the bag.

This a common problem and a real pain in the arse. It's defintely and ACPI / Lenovo hardware/BIOS issue. It would be nice to just blame it on Windows, but it's not.

 

Mine often gives a BSOD when I close the lid while it's busy to go in S3 mode

 

I always found difficult to trace back the root cause for these sleep mode problems. It can be linked to so many things: BIOS, buggy driver, Windows problem, etc.

 

Ubuntu has a battery icon, which provides all relevant information. Use it

 

Linux applications don't have such awkward names