Is a Bluetooth keyboard or USB keyboard better for tablet battery life?

nestor vb June 5, 2013

Hello everyone, I have a huge question on my mind and I wanted your help.

I currently have a Lenovo Ideapad 7” tablet, and I was considering buying a keyboard in case I want to write more comfortably. I am between one fancy Bluetooth wireless keyboard or the usb one that connects via the USB OTG cable.

My main question is about power consumption – which will drain less battery? The bluetooth version or the OTG USB version? My tablet runs Android 4.0 ICS.

Thanks for your answers! Cheers

  1. Jason Cbabe
    June 6, 2013 at 2:33 pm

    USB will always be a little more draining than bluetooth, but it is the easiest to use and set up in my opinion.

  2. susendeep dutta
    June 5, 2013 at 10:08 am

    I think that you'll get satisfied with a forum user's real life test on his device which goes as -

    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.

  3. ha14
    June 5, 2013 at 8:40 am

    well the tablet will power keyboard and usbtogo junction, whereas bluetooth keyboard comes with its own power battery.
    How to select the right keyboard for your tablet

    one problem of bluetooth keyboards is that if connection do not work for some reason and you are on the road badly needing keyboard?

  4. DalSan M
    June 5, 2013 at 2:06 am

    Apparently the USB keyboard uses little more battery life than a Bluetooth one, but not very noticeable of a difference. Bluetooth would be better, especially one with built in touchpad, since you can charge your tablet while still using the keyboard, and the Bluetooth keyboard can be connected to other devices as well and used. This would include some game systems, smartphones, etc. If you can connect your tablet to the tv, then the Bluetooth keyboard would be indispensable.