This has been mentioned as a side-topic in other threads, but can anyone give me a straight answer:

1. If I switch off my tablet and then switch it on a few hours later, does that consume more power than if I just leave the tablet on standby for the same amount of time?

2. If that's the case, at what point does it become worth switching it off to save power? A day? Two days? A week? Or is it never worth switching it off because the battery runs down anyway?

As is apparently from the wildly differing battery life claims, there are probably too many variables here to really say for certain. So, more specifically, what's the consumption of a shutdown and a startup versus 1 hour of idling (say, with 2 SD cars in offline mode).

The convenience factor should also be taken into account here. The device is really designed to be left on 24/7 (the ARM and wifi powersaving are particularly impressive).

Sorry I don't have any hard data.

not sure about exact numer when it pays off but it is measured in days. I think some nokia engineers in maemo-developers list mentioned few times that one reboot is worh of several days of standby.

I've not checked the dev list but I've seen it in a bug report, https://bugs.maemo.org/show_bug.cgi?id=2673#c25

I've wondered about this too. I will say this though, about two weeks ago I had turned off my tablet the night before a class and it had "2 hours in-use time", that particular class was 2 hours long so I figured it would be save just to turn it off right? Well the next day when I got to class I turned it on (after having been left off all night) you would think I would probably have about 2 hours of in-use time left right? Nope! It said "less than 1 day idle, less than 1 hour in use" that means not much left, and it actually ended up being about 5 MINUTES of usage time (on lowest brightness, blah blah), (that was pretty unfortunate too since I keep all my notes on my tablet ) anyway I will say that these days I just leave my tablet on all the time, even if I don't plan on using it for days.

Hope this helps.

I have found that the command line app "battery-status" is far more accurate... it gives you the remaining battery capacity in percentages, instead of trying to "guess" how many hours of use time you have left. You should find the deb for it by searching this forum.

Thank you SO MUCH for all the replies!

I'm doing a tutorial on power saving so I wanted to check with people on here before deciding what to say about switching off or standby.

I think on balance I'm going to tell people to leave their tablet switched on, especially as people involved in tablet development seem to be giving out this advice.

I've certainly heard experts say this about smartphones, that they load and run so much setup stuff when they switch on that it's better to leave them on standby, so this may well be true about the tablets as well.

I don't have hard numbers either, but I've also noticed that booting up takes some juice. I would only switch off my N800 if I had to leave it behind for more than a week. If fully charged I would even stretch that a bit.

It's definitely taking up a lot of juice when powering on.
The power management has not kicked in yet, the screen brightness is at its maximum the CPU probably is running at its maximum speed due to a lot of data being processed and daemons being run, it has to check all the peripherals before putting them into sleep mode or deactivating them, so ALL of them are for sure active and draining power from the battery.
The GPS chip is on initializing itself, the Bluetooth and WiFi chip too and, later, probably they are going go to look for available connections.
The flash memory is being read as the system and daemons and so on (applets, interface, libraries, you name it) load into RAM.
The card needs to be checked and the crawler needs to go look if there are new media files on it...

This alone it's a lot of stuff and almost everything is done at more or less the same time (those seconds it takes to load).

I usually bring it with me in the lab and leave it idle most of the time connected to the WiFi (I could say 95% of the time it's there sleeping and warning me of new IMs or mails, that's it) and at the end of the day the battery indicator is still full.
I use it the evening pretty much to browse the web and chat and reply to some mails every now and then while watching TV or spending some time with my girlfriend.
It usually goes to sleep with me with the battery indicator still full (but I know it's kind of lying to me).
If i let it run (may be I put it in offline mode), the next morning is still full or one bar (only one bar) has gone.
Today is such a day, it's 12pm (time for lunch!) and the battery indicator is half way telling me I have 1 hour of usage and 3 days of idle!
But, sometimes (very rarely and mainly because of modest being stuck trying to download mails) I turn it off the evening and on the morning.. those days it ALWAYS tells me I need to charge the battery.
Always.

And, to be complete, this are my settings: default ones. Brightness settings have never been touched, I've activated the blue led to tell me if it's on or not (that adds to battery drain), Bluetooth is alway on, but not visible (no icon for me) and WiFi is always connected (either in the lab or at home) and during lunch I move to another lab where it automatically switches to that WiFi AP while during the day I go to get some coffee two or three times and there's no WiFi down there (that all adds up to battery drain).

Overall I am VERY impressed on how it behaves when it comes to power management. Very. It's awesome.

You might want to take into account that the locking keys and screen doesn't help. The moment the pop-out camera is pressed, the keypad and screen becomes active. This alone is the reason why I have to keep my NIT switched off most of the time. I'm storing it in my coat pocket and most of the time, I found it switched on without my knowledge. I requested some solution to this problem but didn't get any sensible resolution to the problem. I have a soft pouch (similar to the "sock" delivered with the NIT) but the net effect of that is 10% (I mean, 90% of the time it still unlocks the keys on it's own). I'm waiting for something called "Soft Poweroff" that people have been talking about on the forums. It seems to be broken since the arrival of OS2008 for the N800. I've no idea what it is but hopefully, it's something that requires a little more than plain press on the camera to deactivate the keylock!