I've got an old iRobot Roomba "3100 Pro Elite" whose battery has died. A new Roomba is EUR 300 and upward, so I would prefer to revive the one I have.

It's difficult (impossible?) to find replacement batteries in Austria (Europe), and they are so expensive that I haven't yet convinced myself the cost is worth it. But it would be nice to revive the Roomba as it is in decent working condition, mechanically, except for the cheap rubber treads that I have glued back on.

Do you have suggestions for where to get a replacement battery for this specific Roomba?

Would it make sense to try this DIY approach, considering I've never tried soldering on batteries? I'd hate to have this thing explode in my living room. Where would I get batteries from? The page's discussion thread refers to a U.S. website.

this is what I have: iRobot Roomba 3100 Pro Elite

  • Have you called iRobot? Maybe they only do this in the US, but when our battery died, they sent us a new one for free.
    – noah
    Sep 28, 2010 at 14:52
  • Within warranty, perhaps. This unit is bought more than 3 years ago, and the product itself is probably a lot older. Should have paid more for the latest model back then, rather than paying less for an already-old model... :-/ Sep 29, 2010 at 7:37

2 Answers 2


Ebay - that's where I got my replacement. It's NOT an iRobot manufactured battery pack (nor does it claim to be), but it works fine. I think it came from someone in Hong Kong, and the shipping wasn't bad at all - I don't know how shipping in your area would be.

I looked at opening the pack up and replacing the cells, but I couldn't figure out how to get the thing open without damaging it.

  • Thanks, this looks promising! There are lots of auctions about batteries for "400 4000" models. I'm not sure these would also work in my 3100 model, and the pictures are mostly not the actual batteries but just original Roomba photos.... :-/ Sep 29, 2010 at 12:42
  • Yea, finding the right one might not be trivial - those guys don't necessarily go out of their way to make it easy. I seem to remember hunting around a bit before I found one. Sep 29, 2010 at 20:45

My first recommendation would be to contact the maker of iRobot and see what they can do for you, I know that in the US we can get batteries from them easily.

Now, if you wanted to go the route of building your own battery as it noted in the link you posted, it isn't "that" complicated. You can get yourself some much better detailed instructions on how to build the battery pack using instructions for "Radio Controlled Car Battery Pack" creation as they us the same Sub-C cells for the battery packs.

  • iRobot doesn't exist outside USA, but they have a dealer network. The European shops only have the new models, and only spare parts for the new models. No luck with such old gear. Sep 29, 2010 at 7:36
  • Interesting comment about R/C car batteries. I hadn't thought of that! Sep 29, 2010 at 12:43

Not the answer you're looking for? Browse other questions tagged or ask your own question.