June 28, 2007

 Navigation

   Home Page

 News & Features

   News

 Columns & Opinions

   Publisher's Note

   Boomers

   Pinings

   Longshots

   Techie

 Pop Culture

   Film

   TV

   Books
   Video Games
   CD Reviews

 Living

   Food

   Wine

   Beer
   Grazing Guide

 Music

   Articles

   Music Roundup

   Live Music/DJs

   MP3 & Podcasts

   Bandmates

 Arts

   Theater

   Art

 Find A Hippo

   Manchester

   Nashua

 Classifieds

   View Classified Ads

   Place a Classified Ad

 Advertising

   Advertising

   Rates

 Contact Us

   Hippo Staff

   How to Reach The Hippo

 Past Issues

   Browse by Cover


Don’t believe the hours
Your laptop can last longer, but how long?
By John “jaQ” Andrews  jandrews@hippopress.com

Anyone who’s ever owned a laptop for more than a few months knows that batteries don’t last forever.

Oh, sure, modern batteries have “no memory effect” like in the bad old days, when your computer would figure the battery was completely charged whenever you unplugged it and never charge it past that point again. And with components engineered to draw less power, batteries do last longer than ever.

When they’re new.

Unfortunately, no matter what the manufacturers tell us, it seems like all laptop batteries gradually last for less and less time. The four hours of runtime out of the box might decline to two after just a year, and older models are lucky to run for 30 minutes on a charge.

You can buy replacements, but they become harder to find the older your computer gets. If they’re not newly manufactured, they might have lost some charge before you even buy them. Even reconditioned or recycled batteries from third parties, though, can come close or even exceed your original battery’s life, but eventually succumb to the same fading away.

For truly long-term unplugged computing, there is a compromise position: external batteries. Rather than a custom battery for your particular make and model of laptop, external batteries fit many different types. They’re a little less portable, but a whole lot more convenient than always sitting by an electrical outlet.

External batteries usually connect to the power input jack on your laptop. Some models come with an array of tips to fit the widest variety of machines, while others require that you buy a tip for your laptop separately. The laptop will then think it’s hooked up to a regular old AC adapter.

That is, if the external battery puts out the right juice. If your laptop model is specifically listed, you’re probably good to go. Otherwise, check the stats on your AC adapter. For example, the power brick for the laptop on which this column is typed says its output is 19 volts at 4.74 amps. Multiplying those two numbers together gets you the wattage of the adapter, 90.06 watts. Any external battery should have the same specs as your AC adapter, though a few milliamps of difference shouldn’t hurt.

I tell you those numbers not to awe you with my power of Googling electrical unit conversion charts, but because they can give you a hint of how long a given battery will last. Most external batteries advertise themselves as “four-hour” or “10-hour extended life” batteries or something like that.

Don’t believe a word of it.

Not only does battery life depend on what model laptop you use, it depends on how you use it. Editing a text file takes a lot less power than burning a DVD and defragmenting your hard drive simultaneously. That 90 watts I mentioned above? That’s the maximum my laptop should ever use. In real life, it usually uses less.

To get a good idea of any battery’s real-world life, take a look at your existing battery. Mine operates at 11.1 volts and has a capacity of 7,200 mAh, or milliamp-hours. Multiply volts by amps and I have a 79.92 watt-hour (Wh) battery. An external 80 Wh battery, or one with a capacity of 4,210 milliamp-hours at 19 volts, would run my laptop for about the same amount of time.

I know that’s a lot of math. When in doubt, go for high Ah or Wh numbers and make sure your laptop is listed as compatible. Those will give you the longest run times.


6/21/2007 Get where you're going

6/14/2007 Enlighten yourself
6/7/2007 USB is hot
5/31/2007 USB is cool
5/24/2007 Gadgets for nothing
5/17/2007 Make your gadgets better
5/10/2007 You may now unplug
5/3/2007 Mobile is nothing
4/26/2007 Expand your wireless network
4/19/2007 Expand your wireless network
4/12/2007 Get a newer brain
4/5/2007 Get a newer brain
3/29/2007 Security can be free
3/22/2007 Paper that's not paper
3/8/2007 Use any file
3/1/2007 Audiobooks for free
2/22/2007 What's for sale today?
2/15/2007 Prints in your pocket
2/8/2007 Watch this
2/1/2007 How open is your source
1/25/2007 iPhone it now
1/18/2007 Simplify, simplify
1/11/2007 Vista time!
1/4/2007 Google killers?
12/28/2006 Tech that didn't happen
12/21/2006 Do not want
12/14/2006 Meet the new web
12/07/2006 Extreme price shopping
11/30/2006 They want what?
11/23/2006 Zat zany Zune
11/16/2006 Shop smart
11/9/2006 Your data's new home
11/2/2006 Hotkey heaven
10/26/2006 Computer to go
10/19/2006 Tech news roundup
10/12/2006 A different drummer
10/05/2006 Who needs TiVo?
09/28/2006 Disk drives without disks
09/21/2006 Movies, just click your mouse!
09/14/2006 Laptops for less
09/07/2006 GPS everywhere
08/31/2006 The printer dilemma
08/24/2006 A series of tubes
08/17/2006 More music, more places
08/10/2006 How big is your drive?
08/03/2006 It's a WiFi world
07/27/2006 Fancy a spot of memory?
07/20/2006 Under the sea
07/06/2006 eBaysic training
06/29/2006 You paid money for that?
06/22/2006 Processing ... processing ...
06/15/2006 C:\Run for the border
06/01/2006 The keyboard is mightier
05/25/2006 Geek phone home
05/18/2006 Super highway information
05/11/2006 How to host a site
05/04/2006 If they mated
04/27/2006 Apples to apples
04/20/2006 Flash uber-drives
04/13/2006 Web site, by you
04/06/2006 Ayyy, jaQ's right!
03/30/2006 Choose wirelessly
03/23/2006 Tax programs cometh
03/16/2006 And the Spammie goes to...
03/09/2006 Take in the Vista
03/02/2006 Cheap moviemaking
02/23/2006 Go directly to iJail
02/16/2006 Will you stamp your e-mail?
02/09/2006 War of the machines
02/02/2006 Faster than a speeding packet

01/26/2006 Free software made simple
01/19/2006 The Worst of CES
01/12/2006 Radio you
01/05/2006 Making Movies
A browser is to a car as ...

Behold, the $100 laptop
Beyond VCRs, Part 2
Beyond VCRs
Back-to-school basics
Big Brother is printing
Books without the paper
Essential Gadgets
Get it while it’s hot, used
High-tech garage sale
In touch with the future
Last-minute dork presents
Make your mark
Memory in your pocket
Microsoft must be scratching its head
No strings attached
Plastic junk for Halloween
Power up

Satellite radio showdown

The sound of your voice
There ain’t no such thing as free music
Want to watch cable in every nook and cranny?