I searched, but couldn't find an answer, so if it's already been answered, I apologize in advance (I know how unforgiving this forum can be...)

Anyway, I'd like to get a keyboard for my n800, however I'm stuck on whether to get a USB or bluetooth keyboard. One of the things I'd like to take into consideration is the power consumption of both of them. I normally keep bluetooth off, because I don't otherwise use it, so I'm sure bluetooth would have an effect on my battery life, but would USB ocasionally have a worse effect?

Thanks to anyone who can help!

Depends a lot on the particular keyboard: I've seeb usb keyboards going from 20 to 500 mA. Useless to say the higher the rated power of the keyboard the bigger the impact. Also note that what's printed on cheap keyboards is not always true. I found a small usb keyboard at a local store here (some noname chinese brand) rated 25 mA that drained a full 500 and so was unusable with the tablet.
Although knowing how bluetooth on (and conected to the keyboard) affects battery would be nice... anybody?

I think it's actually very low usage on the BT, unless actually typing. I'd guess if you want to leave it connected a lot, but aren't typing all that much, BT's better. But I have no tests to back that up...

I haven't noticed any higher drain on the battery while using my BT iGo (ThinkOutside) Sierra keyboard, compared to when not using a keyboard at all (and BT off). I've used the keyboard for up to an hour, or hour and a half at the time.

However, I didn't explicitly try to measure the battery drain, I just didn't have any indication there's any problem.

When you're talking about BT vs USB it's usually more a question of costs and convenience than power consumption. BT keyboards generally speaking will cost more money, but give you that "wireless freedom" so to speak; USB on the other hand tends to be cheaper, and doesn't require your device to have it's own power supply, so generally costs less. In terms of power consumption I would hazard that you're probably pretty close (so long as you have a pretty standard USB keyboard and not a crazy high-current one) with BT probably at a slight (not sure if noticable) advantage. I've got a roll-up USB that I picked up for $7 that I've used on the tablet for about 2 hours without seeing any noticeable difference in battery drain; when I checked dmesg though I noticed that the kernel told me the keyboard was only asking for 23ma of power though, so that's got a pretty big impact on it.
I've also got a BT keyboard but I've only ever used it for an hour or so continuously, and again, no really noticeable difference between that and just having BT turned off. My understanding is that BT has been tweaked and optimized in the same way Wifi has, so leaving it on and connected has almost no major impact on battery life unless you're constantly sending/receiving data (i.e. your cat falls asleep on the keys and fills your screen with "FSAFDA...").
In either case the thing to keep in mind is that while the BT might seem like it lasts a little longer since it has it's own power supply, it also can be more of a pain, especially when travelling: 1) Requires a second charger, and 2) Can't use it on a plane. But again it depends what you're primary uses for it are and what you're really after.

Thanks,
-Rob

I think Rob summed it up quite nicely. Just a minor comment to the last point: My Sierra BT keyboard has a single AAA battery, and it seems to last forever. I'm still on the one that came with the keyboard when it was new. Mind, I'm only using it now and then and with long periods of no use, but still - I'm not worried about it and I don't need a charger for it.

Thanks for all the answers/opinions! I think I'll probably end up getting a USB keyboard, because it'll end up being cheaper. Thanks again!

bump.

whats your opionon 5 years later?