External Battery Roundup: Stay Away From The Wall Socket

Staying Mobile Longer

Shopping for a notebook involves a delicate balance between battery life, performance, usability, and price. No two users share the exact same criteria for what they consider the right blend. That’s why we try to evaluate mobile platforms based on their perceived strengths. Take last year's Netbook Buyer’s Guide as an example. We considered the fact that some buyers are willing to spend more for battery life and forgo a bit of performance. Others are willing to pay an extra $100 or $150 to get both. Another group cares more about usability. The list of ways to break even this one specific market into tiny pieces goes on and on.

(Image credit: Jake Edmonson)

If battery life is your number one priority, shopping choices are limited. Clearly, there are notebooks designed for those on the move. But what if you don't want to sacrifice elsewhere to get that mobility? Maybe you just need another hour of run time to get your current notebook through the day. If that's the case, a brand new system doesn't make much sense. 

Even if you already own a notebook that delivers ample battery life, we're certain that there are travel days when even a power-sipping system just doesn't have enough juice to last through closing time. If you spend a lot of time on the road, layovers don’t provide enough time at an AC jack to get you back to 100%. That might mean your in-flight entertainment gets interrupted right before the big climax. Sleeping, talking to unwilling neighbors, and hitting on flight attendants only eats so much time. What other options are there?

There is a solution, though. Check out an extended laptop battery, which comes in the form of an even larger installed battery pack compatible with your existing system. There is a big catch. These batteries (often denser six-cell or nine-cell) weigh down your machine, altering its mobile profile. These batteries stick out the backside of your notebook like a sore thumb, and can turn a sleek thin and light notebook into a clunky desktop replacement.

Fortunately, there is another option, too: universal extended batteries. These batteries don’t plug into your system directly. Instead, they function similar to uninterruptible power supplies (UPS), which we often associate with safeguarding desktops. They are always external units, but often have a small profile that makes them easier to pack for travel, offering higher densities than extended batteries can't provide. And if that wasn't enough, you generally get the ability to charge your cell phone, iPod, and camera from them as well.

After we published our Netbook Buyer’s Guide, one reader posed a question about mobility in the comments. So, during the past two months, we hunted down just about every available solution capable of extending the battery life of your notebook. If you're on the go, this story is for you.

  • lashabane
    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!
    Reply
  • zodiacfml
    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.
    Reply
  • burnley14
    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.
    Reply
  • @zodiacfml

    it's simple really, AC adapter spit out AC, Batteries spit out DC
    Reply
  • nukemaster
    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
    Reply
  • Onus
    Thanks for the comments on Digipower. I've placed them on my personal "Do Not Buy" list.
    Reply
  • Luscious
    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
    Reply
  • a_fortiori
    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?
    Reply
  • shineon2010
    Very good info , alot of products that im having second thoughts about.
    Reply
  • junixophobia
    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
    Reply