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.