Decision trees and self-challenges: how my laptop’s recent battery failure is a great excuse to think

The battery on my Lenovo X61 tablet refuses to hold a charge, and there seems to be no way to fix it. The battery is no longer covered under warranty, so I’ll need to replace it on my own if I choose to. An easy algorithm for decision-making is be to postpone spending money until I can demonstrate really good benefits for doing so. (Or in this case, nine business days before I really need a new battery.) Because I’m curious about the way I might think about other choices, I’m going to think through some of the strategies I use to make decisions. =)

Decision trees

I like breaking things down into decision trees, similar to the technique described by Ken Watanabe in his kid-friendly book Problem Solving 101. It’s useful to figure out what the options are and what their costs and benefits might be. I realized that I actually have two independent choices: what to do with the battery, and what to do with the laptop. Here is my current decision tree.

  • CHOICE A.1: Buy a new battery for my Lenovo X61T
    • Will need this if I sell or give the laptop to someone
    • CHOICE A.1.1: Lenovo battery
      • CHOICE A.1.1.1: – trustable but more expensive; $160-200
      • CHOICE A.1.1.2: Craigslist – potentially $80-100, risk of getting older batteries
      • CHOICE A.1.1.3: Other Internet sources – risk of getting the wrong kind of battery
    • CHOICE A.1.2: Third-party battery $70-90 – risk of scams, unreliable batteries, hazards
  • CHOICE A.2: See if I can get by without one
    • Make my work laptop my main laptop for the moment.
    • Draw with the power cord plugged in.
    • Keep track of the instances when I’d like to plug in, and buy the battery when it gets on my nerves or when I notice myself using the computer much less. Currently using the tablet practically every day, so drop-off should be noticeable.
  • CHOICE B.1: Save up for X220 tablet
    • Longer battery life
    • 12.5″ outdoor-viewable display, more horizontal resolution: 342 extra pixels, widescreen aspect ratio
    • 3.9 pounds with 4-cell battery
    • Dual-array digital microphones – possible use for Skype, podcasting?
    • 2.7 GHz processor option
    • Rapid Drive for faster bootup/access?
    • Instant resume for wireless (up to 99 minutes)
    • Warns when walking away from stylus (heh, nifty; haven’t lost mine yet, though)
    • Gorilla Glass – scratch-resistance could be useful
    • CHOICE B.1.1: Give X61T to J-
      • May still need to buy a battery unless we want to treat it like a PC.
      • She’ll like the drawing bit.
    • CHOICE B.1.2: Resell X61T on Craigslist
      • Will need new battery anyway
      • Will need to sell at a discount because of wear and tear
  • CHOICE B.2: Stick with X61T until I reach the end of my two-year self-upgrade cycle, or until I have strong reasons to upgrade
    • 4.2 pounds, UltraBase, etc.
    • Doesn’t use new buttonless trackpad
    • Bigger wrist rest space
    • Could potentially scoop up X220T on secondary market, or wait for promos

I’m probably going to go with choice A.2 for the short-term choice, and we’ll see how my savings work out for choice B. We’re saving for a fair bit of travel this year, so B.2 is more likely than B.1. Fortunately, I work with two laptops, so it’s fine. My basic choice is good. Here’s another technique I use to examine that more closely:

Estimating option value

Hmm. Well, I can still use my battery-less X61T for drawing, writing, and coding. I’ll need to properly hibernate it before transferring locations, or leave it mostly in one place. I just won’t use it out and about as much. I don’t spend that much time in cafes, so it’s really more the shift between the kitchen and the living room or the basement.

So, what’s the estimated gap between the expected value of a fully-functional laptop and a battery-less one? In my case, probably not as much as it would be for other people, because I’ve got my work laptop in addition to this. The upper bound on value for me must be $5/day – definitely can’t be more than that, and is probably nowhere near that number. The cost is probably just a few more extra minutes starting up and shutting down, and a little less flexibility, which doesn’t translate into a large cost because I can use that time for something else. It might even be a net benefit if it encourages me to use a sketchbook during our upcoming trip. =) Worst-case scenario is that it might cost me an hour of work if I forget to save something, but that’s just about discipline.

The value gap might be bigger for J-, but we’ll see if she can handle it. It’s going to be a big gap if we sell this, but then it’s okay to get a new battery closer to that day. Besides, I usually run my laptops into the ground anyway. This one was an exception. I replaced my Eee after a little less than a year), but that was mainly because J-‘s need for a computer coincided neatly with my curiosity about tablet PCs.

Setting up challenges

Another way to find out if I’m sufficiently interested in something is to ask questions and set myself challenges. For example, if I want to double-check the potential benefits of the fancy new X220 tablet compared to, say, the lower-prices X220 laptop or my current X61T, I can ask the following questions:

  1. Will I draw often enough to make the tablet worthwhile?
  2. Will I need more than 3 GB often enough to make the upgrade to a 64-bit OS worth the hassle?
  3. Will I run into CPU processing limits often enough to make sense to switch?
  4. Will I need the battery life often enough to make the extended battery life worthwhile?

Answers 2 and 3 seem to be “no” at the moment. VMs would be a good use of additional memory and processing power, but I’ve been doing fine with two computers. If I can cope with a battery-less life, the answer to 4 is probably not significant, unless I find myself going to way more conferences and meetings (and if my scanner proves unwieldy). The answer to question 1 is the most interesting.

I’ve taken lots of sketchnotes, but I’ve done fewer illustrations than I’d hoped I’d draw with the X61T. The workflow isn’t as smooth as keyboard + Cintiq, but it’s (semi-portably) fun. I haven’t figured out how to stop GIMP and Inkscape from jittering so much, although MyPaint and OneNote make beautifully smooth lines. I tend to do my sketchnotes plugged in, but I have a few sketchnotes from meetings where power outlets were few and far between. If I use paper notes for the portable sketches (maybe index cards or notebooks?), then I’ll get a better idea of the incremental value of A.1 or B.1. I can set myself an arbitrary threshold – maybe fill a notebook full of out-and-about sketches and notes – and reconsider my decision when I’ve achieved it. Result: Better drawing skills, a habit of drawing, and an idea of how much I might benefit from the infinitely scrollable paper and the multiplicity of colours on a digital canvas.

I’ve exaggerated the level of thought I usually go to for something like this. There’s room in my “dream/opportunity/kaizen” fund for a new battery if it turns out I absolutely must have one. But it’s fun to think through the techniques I might use to decide something, and writing it down now for something that isn’t critical may help me remember it later when I need to decide something more major. And who knows, it might get you thinking about something… =)

(I might end up getting a lot of value out of not having a battery for this notebook. Look, a blog post, and more reasons to draw/sketch on paper! Stay tuned for progress.)

  • Interesting thought breakdown here. I use something similar, where I usually have an idea on what things I would need. As an example, my phone battery life is drastically shortened recently in addition to having lots of dead pixels. I had a choice of upgrading to a smartphone, or downgrading to an even dumber phone than it already is, and buy an additional device to house all the rest of the features I’d need for mobility. I opted for the second option, since an opportunity to buy a really cheap nokia phone came up. I’ll be buying a 3ds when it comes out, and that should have everything else I need (mobile browsing, gaming, limited text editing for notes). It would be coming out cheaper than the first option, but admittedly I’d be losing out on the other features by not getting a nice android phone.

    I like that you have specific yes/no questions that you ask of yourself, to make sure that you are not going to regret your decision. I’ll give this a try sometime, when I’m facing a difficult choice.

  • Here’s a couple to add to your decision tree

    New Century Plaza has two shops I would trust for batteries.
    * Battery Pole (but I don’t know if he has laptop batteries)
    * U-R Computer (the one beside Grotto) is pretty reliable, I get my inks from there and small knick nack electronics. They should have batteries for you

    Runner ups are:
    * J&R Consulting
    * Not the computer store near the south door that normally has something displayed outside, but the one a little more further in. (Sorry don’t know the name but that’s the best way I can describe it ^_^)

    I can check for you if I stop by there when I go to 3600 or eat at the restaurants there since it is close to home anyway.

  • I bought a new laptop battery in August, and already it lasts only 15 minutes on a full charge. The original HP battery performed much better. So I’ll probably spend more to get the HP battery this time ’round.

    But if you want to get a cheap replacement, the websites that specialize in laptop batteries make it very easy to find a replacement. You can enter either the battery part number or the laptop model, and they offer the right one. So choices A.1.1.3 and A.1.2 shouldn’t weigh heavily on your decision, IMO.

    Patricia alluded to opportunity. She saw a deal and that made the decision for her. You can’t plan on that, but it’s good to open yourself to that option. Who knows, with your popularity, someone might offer you a free battery in exchange for an ad on this site!

    One more option is to crack open the battery casing and replace the individual cells yourself. You’ll save money, but, again, you run the risk of getting old cells. The age of the cells and how they’re stored is so important.

  • Sorry if I missed it, but you do have another possibility. There are shops who will rebuild your existing battery pack using (high quality) new Li-ion cells. I haven’t had that need myself, but it would be on my list for sure. The advantage is a higher quality set of cells of known origin, at what may be a reasonable price.

  • Raj Kotecha

    Have you ever looked into electronic pens? I’ve currently got the Echo SmartPen by LiveScribe on my wish list. I’m a little hesitant because I can’t be sure it will really live up to it’s promise and I have mixed feelings about the fact that I’d still be using paper. That said, there’s nothing quite like putting a real pen to paper :-) Any thoughts?

  • Raj: I’ve heard good things about the LiveScribe. I’m sticking with a tablet PC, though, because being able to easily erase parts of what I’m working on is really useful for faking the ability to draw. ;) The only times I get annoyed with digital drawing is in applications that don’t seem to be picking up the pen properly – the lines are jittery. But some apps rock, so I’m leaning more and more towards using apps like Microsoft OneNote, MyPaint (free), and ArtRage instead.

    Scott: With the sudden catastrophic failure of the battery, I suspect it might not just be a dead cell – maybe some of the electronics failed, too. But I’ll keep that in mind for other batteries!

    Raymond: Yeah, that’s what I hear. Spend extra to get a reputable battery, because cheap aftermarket parts have cheap cells.

    Archimedes: I’m going to see what the next month or so is like, and if I go for a new battery instead of a new laptop ;), I might check that out. Thanks for the tip!

    Patricia: I can’t think of any decisions I deeply regret, although I can name some decisions I’m going to make differently next time! <laugh> Besides, something like this is a small transaction in the grand scheme of things. I do love thinking through something in order to get a satisfactory decision (not necessarily optimal). In this case, I did a quick check to see if my default decision was really satisfactory and not just reactive, and also checked out what would make me change my mind. It’s good to make up test cases for your decisions! ;)

    For bigger things, I definitely go into a lot more detail. You can bet that I mindmapped and analyzed the situation quite a fair bit before confessing to W- that I had a crush on him. <grin> Likewise, we mapped out scenarios before we got married to make sure we were on the same page. Ah, the geek life! =)