Battery Life

The Transformer Pad 300 ships with a 22Wh integrated, non-removable battery compared to the 25Wh unit in the Prime. The 12% decrease in battery capacity obviously reduces battery life compared to the Prime, however I believe the panel further reduces the life on a single charge.

The 300 either uses a less efficient panel, a less powerful backlight, or a combination of both as you need to drive the panel at around 70% of max brightness to hit our standard test luminance of 200 nits. The Prime, on the other hand, is capable of reaching 200 nits at 40%. The net result of these factors is a drop in battery life compared to the Prime, and approximately equivalent battery life to the original Transformer:

Web Browsing Battery Life

Note that these are older results for the first Transformer (not on ICS) as I haven't yet had the opportunity to re-run them. I'll be doing that as well as working on our new video playback test over the coming weeks.

I didn't see a huge impact from toggling power saving modes on battery life, although that does say more about the CPU load of our web browsing test than anything else. In general I saw spikes at up to 1.2GHz, but most of the time the Tegra 3 never reached beyond 1.1GHz and more often it operated in its lower frequency states.

The addition of the dock increased battery life by around 50%. Remember that the dock isn't perfectly power efficient, you lose some energy in the charging process and the dock itself consumes energy to power the keyboard and touchpad.

Charging

 


T
he new 18W charger (front) vs. the old 18W charger (back)

ASUS ships the Transformer Pad 300 with an 18W AC to USB wall adapter, although I noticed that the version that came with the 300 is actually a bit shorter than what I got with the Prime and original Transformer. Its power delivery capabilities remain unchanged however. By supplying 18W to the Transformer Pad, the power adapter can perform a complete charge of the 300's integrated 22Wh battery in a bit under 2.5 hours (remember charge current drops after all cells reach a certain voltage).


ASUS' latest Live Wallpaper, the water level indicates battery charge level

Camera Quality Usability and Final Words
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  • B3an - Sunday, April 22, 2012 - link

    "What I'm really hoping for is that ASUS is using its experience in building the Transformer lineup and bringing it to market as practice for the release of a truly perfect, x86-based Windows 8 tablet later this year. Give me the form factor of the ARM based Transformer Pad 300/Infinity (along with optional dock), but with the ability to run Windows 8 Pro and I think we may just have the perfect tablet for users who need a notebook for work but want the portability of a tablet."


    Thats exactly what i want. I'm without doubt getting a Win8 tablet - The question is which one.

    It will also replace my laptop as theres just no need for laptops anymore once Win 8 is out, atleast for the vast majority of people. I finally wont have to have a laptop AND tablet which is a waste of money.
    Reply
  • B3an - Sunday, April 22, 2012 - link

    Come to think of it, it would be interesting if theres also Win8 tablets + keyboard docks that have i5 or higher CPU's in them. We all know their will be ARM and Intel x86 designs with near ARM power levels and similar thin form factors. But what about the high end with i5/i7? Like the Samsung Series 7 Slate but with a dock. Obviously the size will be bigger and battery life lower, but if the docks also included a battery then this would also last longer than a typical laptop of the same spec. You'd basically have a i5/i7 laptop with longer battery life and a detachable display. Infact i'm finding it very hard to think of a single scenario where a laptop would actually be better than a Win8 tablet + dock?!... Reply
  • bleh0 - Sunday, April 22, 2012 - link

    Realistically You would have to settle for ULV Ivy Bridge i3s/Trinity or Atom/Brazos for decent battery life, Even with that you wouldn't be able to make it as thin as a TF300T. Reply
  • Anand Lal Shimpi - Sunday, April 22, 2012 - link

    Haswell :) Reply
  • kmmatney - Sunday, April 22, 2012 - link

    I'd still rather have a laptop and a tablet separate. There is no way I can use a 10" screen for everyday work. Reply
  • marvdmartian - Monday, April 23, 2012 - link

    Agreed. Wish someone would come out with a 12" tablet. While not as light or portable as a 10" tablet, these old eyes of mine won't have to have a 12" screen quite so close, to read text, at a decent screen resolution (let's face it, what good is it, to be able to read text, when you have desktop shortcuts the size of golf balls??).

    I keep seeing that bendable screen technology breakthroughs are coming closer and closer to reality. To me, the perfect tablet would be one with a flexible screen, that can be folded in half to fit in my back pocket, but unfolded to something in the vicinity of a 13" screen. Sort of like what Sony did, with their split screen tablet...... only without the split screen!
    Reply
  • swimtech - Sunday, April 22, 2012 - link

    I hear that too. Lots of us would like just that - an X86 Win8 tablet but there aren't any yet.

    I have to say though that the latest Ipad with that magnificent display will actually get the job done now. Asus has a great device there with better coming - but for those who can't (or don't want to...) wait there is a device available - but yeah, it's not Windows.
    Reply
  • sigmatau - Sunday, April 22, 2012 - link

    The "vast majority of people" will find a tablet useless for most things. Not sure what planet you live on. I work tablet? Laughable. A tablet for school? Laughable.

    These devices are still for only entertainment. Can you imagine typing notes in class on one of these? Or breaking it out at work and trying to prop it against something?
    Reply
  • Souka - Sunday, April 22, 2012 - link

    I, and other IT folk, use an iPad all the time at work...for work...

    Ditched the laptop and use iPad for moving around on campus and meetings.

    my desktop, or any desktop as I have a virtualized enviroment, works for the real work (planning, making spreadsheets, visio charts, programming, etc).
    Reply
  • Naguz - Monday, April 23, 2012 - link

    Yes, it can be useful *while at work*, but I agree with sigmatau - it is not a work device yet, if you concider that most people either need good excel/calc or writes a lot while at work. tablets can be great @work-devices, but not really workdevices - yet.

    But I don't agree with him on the note-taking bit. Several people I know use tablets for notetaking in class - with a full sie BT keyboard. :) In fact, they are much more efficient than me, who tend to alt-tab my way into my mail, facebook, or tablet discussions.

    That said, the last thing I'd want is x86Windows on a tablet. It's more than slow enough on my i7 desktop...
    Reply

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