Over the last 3+ years I’ve spent a rather embarrassing amount of time analysing battery drain on mobile computing devices. It’s become a specialty of mine to look at a device, look at the battery size and then estimate real-world battery life figures for certain usage scenarios although in the netbook world it really boils down to a simple equation – take 30% off what you see on the specifications.

In the world of smart devices (computing and communication devices based around the ARM architecture) the equation is slightly different and as we move to ARM based tablets, pads and MIDs the equation gets even more wobbly because these devices can idle down to near-zero drain rates. Take the 300+hrs standby figures you see on some phones for example. With a 5W battery, that’s a drain of about 16mw, which is 100x less power than even the most efficient of PC-based mobile devices in idle mode.  The problem is, however…

There’s no such thing as idle.

The days of ‘standby’ are long gone as even the most basic of phones are able to play music, access 3G networks, present information on backlit colour screens and run simple background tasks like alarm and event monitoring, location services, email polling and more. Move to a smartphone scenario and that 16mw idle figure is irrelevant. When I tested my N82 a few years ago I was shocked to find out that it could suck 9 batteries dry in a long day of heavy use.

I re-charged the device fully and did a static test using the same apps. Music playing, live GPS tracking (I use Nokia Sports Tracker) and IM via Gizmo. I left the device alone and didn’t use it. After 110 minutes it switched off indicating a 2.1W average drain from the 3.7wh battery. [Source]

Today I installed an interesting app on my N82 and confirmed those findings of nearly two years ago. Using the awesome (for geeks like me) ‘Energy Profiler’ for Symbian Series 60 I lay in bed for about an hour testing out various scenarios. Sure enough, the phone idled down to about 200mw and by simply streaming some music over 3G the figure shot up to 1W. Turn on GPS via the map application and crank up the volume and the device was using over 1.5W. Just cranking up the audio volume added 20-30% power load on the device!

The CPU is out of the equation

Last week at CES Nvidia announced Tegra 2. It’s one of the most powerful ARM-based processing platforms on the planet. Think 2-4 times more CPU processing power than even the fastest smartphone out there right now. It’s amazing and exciting, especially when you known that the CPU cores only take around 400-600mw under full load. Once again, this platform can idle down to an almost frozen state. The platform is slightly too big and power-hungry for small smartphones at the moment but expect to see this in high-end media and internet phones and upcoming tablets and MIDs. The 4-10” screen range.

When you get to screen sizes of 4” and above, something happens that levels the playing field for Intel somewhat. Their CPU platforms (*1) don’t idle down very well but in a typical ‘internet-connected’ scenario on one of these ‘smart’ devices, that becomes almost insignificant as the screen backlight adds such a huge load to the platform that when combined with Wifi, 3G, BT, GPS and audio, the CPU is just 10% of the total load. Swapping Intel out for ARM would save you just 5-10% battery life in an ‘active’ scenario.

Active standby

I’m a big fan of low-power computing and I understand that that most people won’t be using a device all the time so there’s a distinct advantage to use and ARM platform over a current Intel platform (*1) but usage models are changing and it’s now common to find people picking up a phone to use it once every few minutes and when they’re not using it, the GPS, Wifi, 3G and audio is still running. Simply being ‘connected’, polling the internet is going to mean that your device is going to be using 500mw of power on average. Standby is now an ‘active’ or ‘on-net’ experience.

Extreme Battery life marketing

All this confusion and range of figures is great for marketing teams. The ‘all-day’ connected’ expression will be used a lot along with a lot of talk about standby battery life of ‘days.’ Forget it! The average 4-10” tablet device will be using an average 1W to 2W per hour. Leave the screen backlight on along with a few flash and ajax-filled browser tabs running with a 10” slate and you’re in the 4W range. The 10W battery that would fit comfortably in such a device suddenly becomes a 2.5hr battery in that scenario.

Warning

You will hear a lot of battery life BS over the next year. Silicon manufacturers are in a truly critical fight to win in the new ‘smart’ devices market and as a result, they will use every weapon. BE AWARE that as devices get more fun, connected and dynamic, you will use them more and battery life will drop like a fly. IGNORE manufacturers battery life claims and wait for independent reviews. That’s what we’re here for!

Related articles:

How long does your smartphone last in ‘MID’ mode?

How big is an ‘all-day’ Mobile Internet smartphone?

(*1) The upcoming Moorestown platform brings a whole new power control architecture to the table in late 2010. More analysis on Moorestown here.

It would appear as though the SmartQ 7 [Portal page] which Chippy checked out for a while is getting a little refresh. This site shows what seems to be called the ‘SmartQ V7 HDMID’ which is actually sort of clever as the V7 has an HDMI port and is a MID! Beyond the HDMI port, the V7 triple boots into your choice of OS – Android, Ubuntu, or Win CE, and has some under-the-hood adjustments.

The case of the V7 looks to be exactly the same as the SmartQ 7 but it looks like the V7 has some slight technical upgrades inside. Update: Peter in the comments linked us to some more detailed into on the SmartQ V7. The CPU is indeed different. The V7 is using (according to info Peter has found) the Telechips TCC8900 Arm 11 CPU, which may be running as reported, at 600MHz. There is also some hardware acceleration which will hopefully allow the V7 to push 1080P content out the HDMI port. According to the source site, the V7 has a 600MHz Arm 11 CPU, but this is probably actually the same 667MHz CPU in the Smart Q7, (we’ll let those extra 67MHz slide for now). Same CPU maybe, but The V7 seems to be rocking out twice the RAM as the original (128MB vs. 256MB) and the RAM is three times as fast too. The original was DDR @ 133MHz and while the V7’s is DDR2 @ 330MHz. The V7 is also has double the internal storage which goes up to 2GB (and an SD slot capable of up to 32GB) from the SmartQ 7’s 1GB. No word yet on availability, or if the V7 will actually be able to handle pushing HD video through that HDMI port, but we can always hope, and if so, this makes the V7 a more attractive mobile HD theater than even the Zune HD – for me anyway!

Jump to the site for a few more images of the SmartQ V7.

Thanks to Adam for sending this in!

The Q7 may not be a UMPC but there’s a lot to like and a lot to learn from the device.  It highlights the difference between professional and consumer devices very well so in this article I’ve mixed a review of the Q7 with some thoughts about consumer web tablets.

The Smart Devices Q7 has a slow, incomplete web experience, no Flash or AIR, poor video quality, very restrictive ARM11 core, runs a partially re-translated Chinese version of a year-old Ubuntu ARM port, doesn’t have a keyboard, is not good for outdoor use, needs a dongle to get Bluetooth working and has some twitchy touchscreen characteristics. Despite all these scary issues, i’m still using the device many times a day.

Full Q7 specifications available here.

Read the full story

Update: Unboxed, stripped down and tested in over 2hrs of video….HERE.

Update: Unboxed, stripped down and tested in over 2hrs of video….HERE.

I’ve just got back from a spot of moblogging to find the Smart Q7 waiting for me. I wasn’t expecting it until tomorrow so it’s a nice surprise. I have a few appointments this afternoon but I’ll get an unboxing video done and try and be around for a LIVE SESSION with video, audio and Q&A at around 2030 CEST.

My Smart Q7 should ship from China on Friday so it’s interesting to see more live images of the device to try and get a feel for what’s going to turn up next week.

Three things strike me from the pics. Firstly, it’s thicker than expected. Aesthetically that’s not good and I question the 250gm weight having seen this. The second thing to notice is that there is no obvious battery compartment. It could be sealed. Finally, it’s nice to see a stand.

More details and links available in the product pages. I’ll run a live session as soon as possible after receiving it. I still have the Samsung Q1EX from VIA so it will be interesting to put a $750 PC-based tablet up against this $200 ARM-based device.

Via Pocketables. Source: Engadget China.

The $189 Smart Devices Q7 web-pad story gets more exciting today as we’ve received some live pics of the device. ElectroWorld, the strange looking Chinese website that many of us would probably avoid, have come up trumps after we contacted them for a purchase. They also tell us they will have a device ‘next week.’  We assume this will be a sample which could mean a 1-2 month wait for the first production run. We hope we’re wrong but we’ll check it out and get back to you.

At $180, the only real question for gadget fans is, what colour? I’d go for Lime Green just to be disruptive and clash with that brown leather sofa you find in every coffee shop these days.

Click to see full size versions in our gallery.

This isn’t going to be a fast browsing device, the build quality needs to be checked out and there will be limitations on the China-focused software stack but if they get the quality right, (a big ‘if’) and offer some better colours, this is a no-brainer for the coffee-table. I’m thinking TV-Guide, auto-updating Friendfeed, Last.fm radio, public transport timetable, picture frame (tuned to the Flickr UMPC tag of course!), there must be a thousand uses. What would you do with it?

Can you imagine what a dev community would add to this? Maemo, Mer and Android communities would love it. I’m sure ARM’s partners, Techcrunch and the old Pepperpad teams are paying attention too!

Update. I have had further contact with Electroworld and have decided to order. They offered me a Paypal option so I have payed $240 inclusive delivery. Ill have German import tax of 19% on top of that. No dates yet but Electroworld have promised to send more specs when they get the sample on May 12th. First production run will, as is normal, be limited.

Update 2. Electroworld have said that shipment could be next week. Soon after 12th May.