The Amazing Lives of Batteries

I had a kind of crazy experience with a couple of batteries, and since it surprised me a little, I thought it was worth a few words.

So I’ve had this current XPS13 (9380) for three years, and the battery life had recently taken a dive. I mean, sure; over a couple of years, I’d noticed a slight reduction in battery life, and when I eventually checked it the capacity had dropped down to 80-something percent. Disappointing, but it’s my daily driver, so maybe not surprising. However, a month or two ago, I noticed a precipitous drop in battery life and, long story short, the capacity had dropped to 60% of the design capacity – seemingly overnight. I’d unplug it from the power supply and it’d suddenly go from 100% to 60%. And it was draining really fast; that 60% would get me a bit over 2 hours. When new, I was easily getting 9 hours out of the laptop if I wasn’t stressing the CPU.

I’m guessing from the sudden drop in capacity that a cell gave up the ghost, but I’m really not an expert; in any case, I decided to replace it. Dell doesn’t consider the XPS battery to be user-replaceable, so they don’t sell batteries directly, but there are several vendors that sell compatible batteries on Amazon. It’s a crap-shoot, I know, but I did what research I could and picked a horse, and it arrived this morning.

Replacing the battery in an XPS13 is super-easy; easier, maybe, because I’ve already replaced the hard drive, and the hardest part of the job is getting the back off without breaking any of the little clips. Since I’d already broken my clips, there was no issue getting the back off this time. I was pleasantly surprised to see that all of the screws holding the battery in were clearly labeled, and the connector was less fiddly to unplug than I expected it to be. All in all, I think it took me less than a half hour, and maybe as little as 15 minutes. If you’re considering doing this yourself, just make sure you have an appropriately sized Torx set, and one of the Philips screws holding the battery in is really small, so you’ll need a tiny Philips screwdriver as well.

That brings me to the crazy part. Like the fictional frog in boiling water (I’ve read that’s a myth), I’d gotten so used to the degrading battery life that I’d forgotten just how amazing the XPS’s longevity is with a new battery. All the more because the battery looks like little more than a strip of black cardboard; it’s hard to believe that it’s holding so much power, for being so thin and flimsy. The instructions on the battery said it was best to discharge the battery to 3% before charging fully the first time (it also claimed that you should run through several charge cycles to condition the battery, but I’ll probably run out of patience before I’m done doing that); when I powered on the laptop, the battery monitor said the battery was 80% full, and that it predicted 9 hours of run time. Which is crazy! I have to wait 9 hours to run it down before I can charge it, and that’s at 80%! It’s now been running for a while, the battery’s only down to 75%, and the Linux battery tool says 7h30m left. I have to make dinner soon! Then I’m going to bed! It’ll be morning before I can plug this in! Insanity.

So many mixed feelings. On the one hand, I somehow feel batteries should last more than 3 years before becoming unusable, especially if the vendor considers them non-user-replaceable. On the other hand, I appreciate Dell making it as easy to replace them as it is, and I’m crazy impressed they can squeeze so much run time out of such a slender and insubstantial sheet of plastic. It’s nice to know that it won’t be battery life that forces me to upgrade my laptop. op.