What is the impact of leaving a laptop in "sleep" mode (while on battery power)?

How much battery would leaving my laptop at "sleep" mode consume? is the consumption low enough so that it would be safe to leave the laptop sleeping at nights regularily and using it tommorow?

What's the recommended period of time for which I should not turn it off, but let it sleep. (for example, if I'll use the computer in a minute - turning it off instead of making it to sleep will definitely not save battery due to the overhead of turning your computer on and off).

Elazar Leibovich

Posted 2009-09-23T02:40:34.217

Reputation: 744

By "sleep", do you mean suspended-to-ram (also known as S3 in ACPI lingo)? – kbyrd – 2009-09-23T03:17:01.103

I don't think so. Isn't "suspend to ram" called hibernate? – Elazar Leibovich – 2009-09-23T16:23:47.033

No. Hibernate (S4) is suspend to disk, then power everything off. – kbyrd – 2009-10-06T03:19:56.010

My bad. I ment suspend to RAM indeed. – Elazar Leibovich – 2009-10-07T10:51:11.593

Answers

I asked almost the same question here.

As for the shutting down completely thing - Windows needs to be rebooted once in a while to complete certain scheduled tasks. I would say to at least attempt to reboot once per day, but other than that, you should just sleep it for a quick launch back into the computer.

You can easily leave the thing overnight on sleep mode and it won't drain much battery at all.

Breakthrough

Posted 2009-09-23T02:40:34.217

Reputation: 32 927

2Reboot once a day is overkill. I use hibernate and don't typically need to reboot other than patch Tuesday and an occasional BSoD. – Brian Knoblauch – 2009-09-23T13:22:12.537

Rebooting once a day is "overkill"? I shut my desktop OFF every night, and that's overkill compared to putting it to sleep mode?! – Breakthrough – 2009-09-23T13:53:31.737

I think he meant overkill in the sense that windows doesn't have scheduled tasks that would need you to reboot every day. I turn my desktop off every night, but it's certainly not necessary. – Malabarba – 2009-10-09T16:01:51.477

D Connors - I don't think most consumer desktop PSU's are meant for a constant duty cycle... They need to be cycled once in a while (e.g. at night). – Breakthrough – 2009-10-10T03:41:52.423

It depends on your system.

Most people I know using modern laptops use sleep as the most common method of leaving the machine. For laptops I have had, I always let it sleep overnight or even over the weekend. From a max battery, it may last several days.

However, I know others who rarely use the laptop so they hibernate instead of sleep. For them, the laptop is used maybe once every couple of weeks.

kbyrd

Posted 2009-09-23T02:40:34.217

Reputation: 2 067

+1 I put my laptop to sleep every night, never had a problem with the battery being drained. They only time it might be a problem is if it was already (really) low. But new laptops manage just fine. – Ivo Flipse – 2009-09-23T06:34:47.850

I leave laptop regularly at sleep overnight. Consumption is low enough to last for more than a week on my model.

While consumption does depend on motherboard and other components, you should be able to get few days of sleep without problems.

Throwing laptop to sleep is very easy to get used to and I don't even recall when last actual reset occurred on my computer.

Josip Medved

Posted 2009-09-23T02:40:34.217

Reputation: 8 582

Regarding how much battery it would consume varies based on processor, motherboard, and additional onboard components. As far as a "recommended time", it is a personal decision and up to you and your environment. I have my sleep disabled. I occasionally force it to sleep when I want to for extended periods of time (30mins or more), but it's usually always on except for the trip to/from work, so i just shut down. vista performs better that way anyway.

Joshua K

Posted 2009-09-23T02:40:34.217

Reputation: 771

I would not put a laptop to sleep overnight. If you really want to keep it "running", look for a hibernate option instead. But the best thing to do is save your work and shutdown. Laptops really aren't intended to be left on all the time.

Joel Coehoorn

Posted 2009-09-23T02:40:34.217

Reputation: 26 787

2"Laptops really aren't intended to be left on all the time." - Leaving a laptop on is NOT the same as sleep mode. Using enough battery power to save the contents of the RAM is quite marginal, drawing VERY little current. – Breakthrough – 2009-09-23T13:01:02.333

It's not the same as shutting it off, either. – Joel Coehoorn – 2009-09-23T13:05:13.643

It's like a battery that saves the time in your watch or your PC when it is FULLY shut off. You're just providing enough voltage to keep contents available. – cp2141 – 2009-09-23T13:06:51.003

Depends on the system. I never had luck with Windows laptops going to sleep and waking up reliably. The best alternative to shutting it down was hibernate. This is almost always because of poorly written drivers.

My Macbook Pro, however, sleeps every time I shut the lid and wakes every time I open it... reliably. I never shut it down or reboot it unless an update requires it. It's one of the features I like most about Macs. I don't even worry about the battery running out, because if it gets that low (reserve power), the Mac is smart enough to save the system state and power itself off so next time you plug it in, you're back where you left off.

churnd

Posted 2009-09-23T02:40:34.217

Reputation: 4 228

Newer windows version will do the same, when suspending to RAM they also suspend to disk. – Malabarba – 2009-10-09T16:05:36.197