How-To: Resurrect a Dead Trimmer

I own a small beard/sideburn/other trimmer that I get quite a bit of use out of. I don't use it to cut my hair evey 3 or 4 weeks; I have another one for that. Instead, I use it to make my sideburns the desired length and angle, to trim the hair around my ears---which lets me go another week between haircuts---and to trim the hair around the back of my neck after a haircut.* The particular model I own has several different-sized detachable cutting heads, which fact makes it extra useful.

Anyway, the thing started acting up on me not too long ago; it just wouldn't hold a charge. I suspected that the batteries were at fault, especially since consumer electronics containing rechargeable batteries often use low-quality batteries, and said batteries often loose their capacity after comparatively few charge cycles.

Not wanting to lay out the cash for a new trimmer when I could probably fix mine, I pried open the case, revealing guts of the device:


As you can see, it uses standard AA-sized cells. If I'd been more careful with my camera, photo below would show that the particular batteries in this model have a nominal capacity of 600-mA-hr.** That stated capacity isn't great, and I can assure you that the batteries were doing much worse than that in practice. I happened to have 12 rechargable double-As in the house at the time, all of which were rated with higher capacities. I wanted to reserve 2 sets of 4 for my RC transmitter, which left me with twice as many as I needed to fix this problem. Groovy.


There was just one very minor wrinkle. Despite the blurriness of the pic, you can see that the two AAs were permanently wired in series by a thin metal---steel?---strip. I duplicated this arrangement with my new cells using a short length of fine-gauge wire:


I inserted the new double-As into the trimmer, snapped the case closed, and charged it up. Guess what? No luck. Crap. And here I thought I was being soooo smart.


I realized, after cracking open the case and tracing the trimmer's wires more carefully, that I had put the batteries in wrong orientation, left-to-right. I repositioned them, reclosed the case, and recharged the batteries. It worked this time. Ta-daaa!

So, the take-home message is this: Don't let The Man keep you down by buying new consumer products when they stop functioning; reach for your tools instead.

* Actually, I usually get Alison to do that last part. Ah, the joys of marriage.
** Or mAh, if you prefer.