At what point does a big battery defeat the purpose of mobility?


Msiwind9cellThat’s the question I have after getting a look at a third party 9-cell battery available for my MSI Wind. The 7200 mAh power pack runs around $115 and also lets your Wind run for nearly ten hours on a single charge. I haven’t seen any reports on the weight of the battery yet and it clearly causes the backside of the netbook to rise up, providing more of an angle to the typing surface.

Common sense tells me that this unit would weigh around 50% more than the 6-cell battery I currently have. While I’d have no qualms about ordering a second 6-cell battery if I could find one, the solution of carrying more battery cells is starting to get old. We continue to see hardware developments reduce the amount of required energy a device needs, but we’re still stagnating on battery technology in general. We’ve heard about fuel-cells and silver-zinc batteries for a while, but nothing has hit the market yet. Clearly, there’s demand for higher-powered and more efficient battery technology, so what’s the holdup?

(via SlashGear)


James Kendrick

Electrovaya makes some decent external battery solutions that I’ve heard good things about. They are expensive but offer long run times when needed.


I had the exact same question come to my mind when I wanted to extend the battery time on my zd7000. Folks who use 17″ laptops know they’re big and heavy.

I guess it all comes down to runtime. With 2 hours a battery, I would need 2-3 spares to get 8 hours, and I didn’t want to carry and charge 4 separate batteries. I wanted ONE big battery that would power me for a whole day and recharge overnight.

I found a company online that deals with li-poly-ion batteries and also does prototyping. Their suggestion came in the form of a giant slab battery that was the same size as the laptop itself (about 17x12x2) and would sit under the laptop, raising the height and tilting it at an angle. The promised capacity would have given me 8-10 hours, however the asking price was so exorbitant I had to give up the idea.

I like the fact that with a slab battery you can keep it under the laptop or have it sitting down beside you in your bag and just connect a cable to your laptop. Elektrovaya made some good ones a few years ago, but they have nothing suitable for 17″ laptops in size or power.


This is why I went to a Mac. At some point in the PC world, hardware designers though it was ok to design around a 4 cell battery pack. Almost no PC maker sells PC’s without “stick-out” battery packs that will net more than 2 hours of work time.

Why is it so hard to make a 1″ thick laptop less than 7 lbs with the AC adapter and still get 4-5 hours of battery time?


I like the slaps that attach at the bottom of the device, like Dell offers it now. I still use an old IBM Thinkpad X40 with a 8-cell battery that hardly sticks out and a battery slap at the bottom, gives me up to 11 hours with the screen brightness turned down and wifi off, perfect for typing on plane rides. I wouldn’t like a battery like the one in the picture.


Excellent point, GoodThings2Life.

If they’d make the battery extend from the back, rather than the bottom, these things would be much more attractive.


I don’t object to large-sized or even high-weighted batteries. I object to poorly designed geometries for those batters that make it obnoxiously uncomfortable to be mobile with them.

borax99 (Alain C.)

As pointed out above, I’d rather schlep a horking big battery than have my machine catch fire due to a hastily-developed newfangled kind of battery !


At what point does a big battery defeat the purpose of mobility?

Based on that picture, I’d say at that point right there.

There’s no way I’d put a battery that size on a netbook sized device.


The real problem is with density, the more potential energy you cram into something the more energy it contains. That is mostly a problem when something malfunctions i.e. batteries catching fire, with increasing the density you get explosive batteries. I saw a demonstration a while back on some of the batteries used by special forces that keep their electronics running for several days. But those batteries if placed in a camp fire have the explosive power of a stick of dynamite. Very cool to see but not something I would want to carry on my person or want other to take on a plane.


I think for me, the 9-cell would only become useful on something like a 10 hour flight and I needed the power. But the chances of that are slim these days. If I was taking a 10 hour flight, i think I’d be sleeping for most of it, and would be fine with the 6-cell which I currently have.

I’d agree with Bob though, the powercord is less mobile than the battery. Which brings me to a complaint I have…these extra long cords are convenient, but super annoying and bulky! Would be nice to have the option of a super short power cord for traveling.


The first battery to establish that unless you have a windlass you will be windless. :-)

Bob Russell

For me, it all comes down to this:
1) Less than 10hrs is not sufficient for me
2) Plugging in a power cord is less mobile than an heavy battery.

Until netbooks and laptops reach a (real-world) battery life of about 10-12hrs, I think there will be a big market for extended batteries – even at the cost of mobility.

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