The case of the mysteriously shrinking laptop battery

The case of the mysteriously shrinking laptop battery

We just reviewed a new retail-specific version of Dell's popular Inspiron 1525 laptop, dell laptop battery,and found ourselves wondering why this new system's battery life was so poor compared to its very recent (and largely identical) predecessor. How can two versions of essentially the same laptop have a difference in battery life as big as the 3-hour vs. 2-hour one we found? We looked a little closer and found a potential culprit.

Both $650 laptops (the newer 1525-139B and the older 1525-121B) have six-cell batteries, but that's not always the most useful number to look at. Most laptop batteries are labeled for 56Wh (or watt hours), which means they can hypothetically power a 1-watt load for 56 hours. The 1525-121B had a standard 56Wh battery, while the 1525-139B has only a 41Wh battery, which one would never notice without taking the battery out and reading the fine print stamped on it--as the batteries (and systems) look pretty much exactly the same.

Thus,Inspiron 710m, our shorter battery life, and one more area where budget-minded PC makers are apparently trying to shave a little cost from their systems. So the lesson here is that there's now one more bit of fine print you need to read carefully before buying a laptop.

Read the full review of the Dell Inspiron 1525-139B here.

Note the two different Wh ratings on these Dell 1525 batteries.

New York native Dan Ackerman, a former radio DJ turned journalist, has written about technology and music for publications including Spin, Blender, The Hollywood Reporter, and USA Today. He hosts the weekly Digital City podcast and the New York edition of Editors' Office Hours.F5136, Dan's new album, Tales Out of Night School, is available now. E-mail Dan.

Topics: LaptopsTags: Dell,Inspiron 1525,battery lifeShare: Digg Del.icio.us Reddit Yahoo! BuzzFacebook

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I bought a dell 1525, teched out with 4 gigs of ram and a 2.4 dual core, and it only gets less then an hour on the most efficient settings. the battery chart when i bought it didnt tell you anything usable, and i thought, hey, i dont need more then say, 2 hours. instead i get 45 minutes, which is unusable. i was really, really ticked. they've just blown me off at this point, and it looks like i'm going to be stuck with it. they've lost my business.

No doubt this trend reflects penny pinching.

My old Dell Inspiron 5100 had a dense 12-cell, 96 Wh battery featured standard - though this system needed the extra capacity to be mobile, since the processor was a desktop-type Intel P4, and the 15" LCD probably wasn't as efficient as the same screens today. Still, when the battery was new, I could run the system with internet on for 3 to 3.5 hours (screen on low brightness).

My relatively new Dell Vostro 1400 (14.1" screen, Core 2 Duo processor) has the Dell 6-cell, 56 Wh battery. Since the processor and screen are much more efficient, and there are many more power-saving/efficiency features onboard, I can obtain ~4 hours of life with wi-fi (screen on low brightness). So, the system's efficiency and conservation features were able to keep pace with the cut in battery capacity. 312-0305 battery .The newest cuts in capacity come in advance of the available efficiency/conservation tech to match.

What is this all about? My 9 cell battery on my Dell is supposedly 'superb' with 80Wh. When I bought this laptop brand new this battery could last for up to 5 hours of operation without being charged. That was two years ago. Now this same battery could barely do half an hour. Lesson is that we should not concern ourselves with how much Wh we are allotted for our budget computers. As far as I am concerned Dell, HP, Sony and other major laptop manufacturers might as well include 20 Wh batteries with their laptops in order to decrease pollution,Inspiron 600m, consumption and their bottom line - which they can pass on to you. Though unlikely. SOHO, NYC

What is this all about? My 9 cell battery on my Dell is supposedly 'superb' with 80Wh. When I bought this laptop brand new this battery could last for up to 5 hours of operation without being charged. That was two years ago. Now this same battery could barely do half an hour. Lesson is that we should not concern ourselves with how much Wh we are allotted for our budget computers. As far as I am concerned Dell, HP, Sony and other major laptop manufacturers might as well include 20 Wh batteries with their laptops in order to decrease pollution, consumption and their bottom line - which they can pass on to you. Though unlikely. SOHO, NYC

My 1525-121b that I bought from Best Buy in September 2008 has a 48Wh battery.Inspiron 500m, So, the progression may have been 56Whr (reviewed by CNET), then 48Wh (purchased by myself), then 41Wh on the new 1525-139b

I wish I would have learned more about laptop batteries prior to my purchase! Live and learn.

Lithium batteries have a little-publicized "half-life" of two years. And by half-life, i mean "useless" life. While it's true they have no "memory" like Ni-Cad and NiMH batteries, their overall life expectancy in current mass-produced form is only about 3 years of "usefulness", and while some more expensive Lithium-based batteries have a better "useful" life, what you've experienced is sadly on-par.

What's worse, is the electronics used to regulate charging,Inspiron 510m, discharging, balancing and overall management of your cells rarely do so in a fashion that promotes battery longevity and power. On top of that, I can say from personal experience of tearing apart many a "bad" laptop battery to pilfer the cells inside that about 8 times out of 10, only one of the three or four cells in the battery is "shot" while the rest are in healthy shape.

If you buy a laptop again, check and see what the store's extended warranty offers in terms of battery replacement. If you can get an extended warranty of 3 years for less than $150, it may be worth it as a future investment to replace the battery alone at that time.