Laptops + physics


I’m not sure if this is an issue for everybody, but battery life is a serious issue with me and my laptop. This is compounded by the facts that:

  1. The PowerBook’s battery life isn’t that great. About 3 hours max if i turn my screen brightness is at the lowest and all I’m doing is writing text/code.
  2. Sockets are hard to come by at Tech-Ed.

So i’m usually always paying attention to what my battery life is at and what I’m going to need to do to make sure that I can stay up. However, there’s a bit of an issue with this system. At one moment I might look and see that I have 1 hour left, then a couple of minutes later i look and I’m down to 20 minutes. What happened!!! Right about that time I start realizing that my … um… upper leg area is starting to burn. I open up top and what do I find? Some process like iChat or Entourage has starting sucking up 100% CPU for a few minutes straight. I quickly try to figure out why and stop the offending process, but I’ve already ended up losing like 20+ minutes that I could have been working.

I know about graphical views of battery life (i use iPulse but don’t like how much CPU it uses) but I’m unsatisfied with them. They’re good at showing you your current velocity, i.e. at this rate how long till your battery will be gone. However, they’re really bad at telling you when you’ve suddenly started sucking up an unreasonable amount of power. What I’d like would be some kind of accelerometer that would tell me that (even though I have 2/3s of my battery available) I’m draining at really rapid rate.

Any tips/tricks on making sure you can really maximize battery life?


Comments (6)

  1. Sean Harding says:

    Yeah, an app that warns you when your power consumption dramatically increases would be neat.

    Kill wireless and bluetooth if you’re not using them; they suck power. Of course, I usually find that when I’m working without a power cord I’m also working without an ethernet cable, and I almost always want to be on the network, so I gotta leave Airport on.

    I just got a new Powerbook a few weeks ago and I was amazed at how much longer the battery lasts than the one on my TiBook does. I’ve been using laptops (and other things with rechargable batteries) for quite a while, so I’m well aware that the battery life will deteriorate over time. But I’d gotten so used to how quickly the battery on my TiBook died that I’d almost forgotten it can actually be usable without a power cord. The new one seems like paradise in comparison.

    Maybe I just need to start buying new batteries every three months.

  2. I’ve started travelling with a power strip. Ive used it mostly in airports so far. The idea is that if I have a power strip maybe I can get people to share their power sockets with me. Haven’t tried to do that yet but it will be interesting to see if it works.

    But I sure could use a utility like you’ve described. I have also seen the meter go from 1 hour to 20 minutes in no time flat.

  3. besides bluetooth and and wireless lan, modem is also candidate to be killed. Turn off unncessary service (e.g. web sharing) and free more memory and processor cycle.

    Also, avoid physical moving of any parts (e.g. fan and hard disk). get cooling stand like those from http://www.koolsink.com .

    be aware that ‘top’ is also cpu-hungry on os x. take the hint http://www.macosxhints.com/article.php?story=20040213045335693 to reduce the impact.

    Perhaps Apple should introduce Power over Ethernet support for powerbook (look those in latest airport extreme).

  4. King-On: Thanks for the excellent hint! I knew top was a hog (and so I only run it for a few seconds at a time to see what the problem is) but now I’ll use this suggestion instead!