Posted by Matty
As our Roomba started getting older, we noticed that he didn’t have the same pep. He would peter out after vacuuming for 30 minutes or so, and he wasn’t doing the best job, either.
I checked my manuals, and tried reconditioning the battery, but to no avail. There was no way around it. Roomba needed a new battery.
I could have just bought a new battery from irobot.com, but where’s the fun in that? How could I turn that into an article?
Truth is, the idea of buying a new battery made me grumpy. To purchase a new battery from irobot would cost $70+. It’s not an extravagant sum, but it is almost half of what I paid for roomba in the first place.
Time to do some research.
I found out that a roomba battery is little more than 12 sub-C batteries (sub-C batteries look just like regular C batteries without the nipples on top). Surely, 12 batteries could be found for cheaper than $70.
On eBay, I purchased a ready-made battery pack for $28 (plus $10 shipping), that came with a special screwdriver necessary to open the original battery case. The replacement battery has better specs and lasts longer than the original roomba battery did when it was new. It wouldn’t be that much harder to build the pack from scratch, but $38 seemed fair.
It took about half an hour to replace the battery pack. The most difficult part is taking apart the casing. It turns out that iRobot would rather that you buy a new battery. First they use proprietary triangle screws on the casing. Then to be really sure that you can’t get at it, the casing is glued together. arrgh.
Once you get the case open, it’s a simple matter to drop the new battery in and solder the old clips on to the wires.
The new battery is like Viagra for roomba. He’s full of vigor again, and vacuuming up our messes like a roomba half his age. He lasts about 2 hours now, more than enough to keep our floors shiny and free of cat hair. More details of the build in the pictures.
So, I saved $35-40 and wasted 30 minutes of my life. I’d call it a wash, except that it’s always more fun to build something than to buy something. Oh, and I got a new fancy triangle screwdriver.