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Test Setup

External Battery Roundup: Stay Away From The Wall Socket
By
Test Hardware
Processors
Intel Atom N450 (1.66 GHz)Intel Core i3-350M (Dual-Core, 2.26 GHz)
Memory
1 GB DDR2-667
4 GB DDR3-1066
Graphics
Intel GMA 3150
Broadcom Crystal HD
(disabled)
Intel HD Graphics
Notebook
Inspiron Mini 10 (1012)Dell Vostro 3300
Adobe Flash Player
10.1.102.64
Operating System
Windows 7 Starter
Windows 7 Professional 64-bit
Graphics Driver8.14.10.2117
8. 14.10.2226


There is a long back-story to the battery life benchmark used in this review, which we'll save for some other time. What you should know is that it is similar to BAPCo’s MobileMark, but it differs in a few ways. Like MobileMark, it is a workload-based benchmark, running processes through several programs. However, this is a benchmark that I have coded from scratch, so that is where the similarity ends.

We want to stress real-world usage, which is perhaps one of the biggest reasons we decided to have at an in-house-developed benchmark. This benchmark mimics what you should expect from everyday life. Right now, I have programmed the battery life metric to simulate a user typing at ~45 WPM and reading at ~200 WPM. So, this is a “Real Life Use” benchmark, hence the name: RLUMark (at least until I think of a better name).

Since we are testing netbooks, there is no need to include content creation programs like those from the Adobe CS5 suite. This limits benchmarking to the General Use Battery Workload.

This workload consists of the following programs

  • IE8
  • Excel 2010
  • Word 2010
  • Outlook 2010
  • WMP12


We will try and keep the benchmark as up to date as possible. Right now, everything has been made current up to 11/20/2010.

In addition, we are always going to benchmark systems as they ship, including their default battery profiles. There is no clean wipe of the OS. In real life, when you buy a notebook, system vendors rarely include a blank copy of Windows 7. Some of the included software is useless, such as trial software, but others programs are important for functionality, for example, ThinkVantage’s Power Manager.

Beyond turning down all the “special offers” when starting the system for the first time and installing Office 2010 Professional Plus, we do not disable or uninstall any software. Bloatware will naturally hog more system resources during the benchmark process, so we want to encourage manufacturers to cut down on this trend. I want to make a point that the time it takes to complete a benchmark workload is unaffected by included software.

Test Conditions for All Systems:

  • Windows 7, all patches updated to 11/20/2010
  • BIOS updates, current as of 11/20/2010
  • Master Audio Volume: 50%
  • System Drivers, current as of 11/20/2010
  • Graphic Drivers, current as of 11/20/2010
    • GMA 3150: 8.14.10.2117
    • Intel HD Graphics: 8. 14.10.2226

Some vendors tweak their Windows 7 battery settings a bit in order to maximize battery life and longevity. There isn’t anything wrong with this. Every company has a different battery strategy that it believes is the best for its system. For example, some notebooks are hardwired to force hibernation at 5%. Other systems will let you go all the way to 0% and just die, no matter what you set in the battery profile. We are going to be testing at default shipping settings under the “Balanced” battery profile.

Some manufacturers have a different name for this profile, but this will always be the “Recommended” Windows 7 profile. To simulate the same visual experience, we only “untweak” the display settings to retail Window 7 settings. In addition, all displays have been set to maximum brightness, which is roughly 200 nits for both notebooks. I specifically choose max brightness over the standard 100 nits because most people tend to use the highest brightness setting. Our previous standard of 100 nits applies only to notebook reviews, because we need to standardize the brightness setting across multiple systems.

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  • 0 Hide
    lashabane , March 9, 2011 5:18 AM
    Excellent article. I had an idea that this stuff was out there but never really bothered to look. If the 4-5 hours I get from my Asus 1215t begins to not cut it, I now know where to look. Thanks!
  • 0 Hide
    zodiacfml , March 9, 2011 6:41 AM
    I did not understood any of the technical reading especially the part about the desktop PSU.
    At one point, it is stated that AC adapters have higher voltage than the battery on a notebook so that it can be charged. Then, how can a external battery damage a notebook's electronics with a higher voltage (only if it's too high)?

    It is not stated how to set the external battery voltage correctly. What then is the correct voltage? Correct me but I believe the voltage has to be equal that of notebook battery.
  • 0 Hide
    burnley14 , March 9, 2011 1:22 PM
    It's pretty remarkable that after page 2 I could guess who the author of this article was (without looking of course) due to the thoroughness and good grammar/lack of typos. Hats off to you yet again, Mr. Ku. Job well done as always.
  • 0 Hide
    Anonymous , March 9, 2011 1:43 PM
    @zodiacfml

    it's simple really, AC adapter spit out AC, Batteries spit out DC
  • 0 Hide
    nukemaster , March 9, 2011 2:16 PM
    zodiacfmlI did not understood any of the technical reading especially the part about the desktop PSU.At one point, it is stated that AC adapters have higher voltage than the battery on a notebook so that it can be charged. Then, how can a external battery damage a notebook's electronics with a higher voltage (only if it's too high)? It is not stated how to set the external battery voltage correctly. What then is the correct voltage? Correct me but I believe the voltage has to be equal that of notebook battery.

    Your guess is actually right. The battery with its voltage set too high can damage the notebook.
    If you need to know the voltage required, you just check on your laptop AC adapter or power brick. It is not always the same as the battery.

    For instance, a Compaq R3000 has an 18.5 volt AC->DC(120w) power supply and its battery is only 14.5 volts. The voltage regulators in the laptop(in the charging system) it self cut it down to the needed 14.5-15volts to charge the battery.

    Also note that the AC adapter does NOT spit out AC it in fact spits out DC(it has a rectifier to convert AC to DC).

    As you can see by this picture(you have to click the link), The adapter takes in AC 120V and spits out DC 18.5V. AC is shown with a ~ and DC with a --_---_-- cant make it on here, but you get the point.
    http://img269.imageshack.us/img269/1950/powerw.jpg
  • 0 Hide
    Onus , March 9, 2011 2:55 PM
    Thanks for the comments on Digipower. I've placed them on my personal "Do Not Buy" list.
  • 0 Hide
    Luscious , March 10, 2011 6:29 AM
    Quite a different experience on my end testing the Energizer XP8000 and XP18000.

    For my smartphone and MiFi, the XP8000 just can't be beat. 5x runtime guarantees me 20+ hours of 3G broadband and week-long phone use. Being barely bigger than a Blackberry, I can effortlessly stash the XP8000 on my belt, and charge my smartphone while I walk.

    The XP18000, on the other hand, was a huge disappointment. Using a Toshiba NB305 netbook, it was incapable of recharging the factory 6-cell battery while powered on, and could not provide 2 full charges while powered off. For my usage scenario, that's a failure, as I plug in the external battery when my netbook hits 3% critical, right before Windows does a force shutdown, allowing me to continue working.

    Using this deplete-charge-deplete approach SHOULD allow me 14+ hours of continuous power-on time, except that even the beefy XP18000 couldn't get through 1 netbook charge. Had it been capable of providing one full charge powered on, or two full charges powered off, I would have recommended the XP18000 as well.

    http://lgponthemove.blogspot.com/2010/07/accessory-corner-3-energizer-xp18000.html
  • 0 Hide
    a_fortiori , March 11, 2011 3:05 AM
    Nice article. I wonder if these units can be used as a mini-ups for equipment like a NAS, routers and modems. It would be great if you could wire these with the NAS, and be sure that a power outage wouldn't damage the NAS. Considering that the NAS units typically consume much less power than a notebook, these should be able to cover 4-5 hrs of power outage (?) Any thoughts?
  • 0 Hide
    shineon2010 , March 15, 2011 6:12 PM
    Very good info , alot of products that im having second thoughts about.
  • -1 Hide
    junixophobia , March 15, 2011 8:24 PM
    shineon2010Very good info , alot of products that im having second thoughts about.


    Just buy an automatic inverter that works for hours with a car battery
  • -1 Hide
    junixophobia , March 15, 2011 8:25 PM
    shineon2010Very good info , alot of products that im having second thoughts about.


    Just buy an automatic inverter that works for hours with a car battery
  • 0 Hide
    Anonymous , March 15, 2011 8:33 PM
    Im missing the portable powerstation, especially the spps-200.
    i wonder how that scores against the others.
    i think they are from novuscell
  • 0 Hide
    junixophobia , March 15, 2011 8:35 PM
    sorry guys, just gettin the hang of this...
  • 0 Hide
    Onus , March 15, 2011 9:39 PM
    If you deep-cycle a car battery, you'll kill it in a matter of weeks, as its thin plates deteriorate. For deep-cycle applications, you want to get an AGM battery, containing much thicket plates; and even then you don't want to drop the SOC too much between charges, perhaps 60% is the lowest you should go.
  • 0 Hide
    Anonymous , April 13, 2011 10:54 PM
    Carrying an extra battery adds a lot of weight. And once the battery is depleted, you are dead in the water if the power socket is out of reach.

    If I am going off grid, I would rather bring a solar panel and charge the battery I already have in my device.

    http://leicadig.blogspot.com/2011/04/digital-camera-off-grid.html
  • 0 Hide
    acku , April 13, 2011 10:56 PM
    Which sonar panels are you looking at? I use Brunton myself.

    Cheers,
    Andrew Ku
    TomsHardware.com
  • 0 Hide
    agnius , April 13, 2011 11:13 PM
    I am debating between Brunton, Powerfilm and Voltaic.
  • 0 Hide
    acku , April 13, 2011 11:14 PM
    I have all three. What's holding up your decision?
  • 0 Hide
    agnius , April 13, 2011 11:34 PM
    Andrew,

    According to my calculations I would need about 25-30W to power/charge a netbook directly and charge my camera battery.

    In theory Solaris 26 could do the job, but I am not sure - I have not read any reports about it. I was planning running Targus DC adapter from Solaris 26 straight into a netbook (I had HP Mini but it broke so now I am looking at Lenovo X120e as a replacement).

    Also, I read that CIGS panels after being stored in the dark take days to reach their peak output. Solaris is CIGS, PowerFilm 30W is silicon which does not have that problem.

    But PowerFilm 30W is also considerably larger which makes it less feasible to deploy while riding. Hence I am looking at Voltaic panels which are much smaller, but I am not sure how to route power without an intermediate battery from them (because they are 20V).

    I am stuck in this decision loop while looking for more information.
  • 0 Hide
    acku , April 13, 2011 11:38 PM
    Are you only trying to charge the camera and netbook at the same time? I assume the camera charger requires an AC outlet?
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