Mine is the 800 seiries. It had a short run cycle, going dead quickly and not cleaning well. It recharged to green in less than 2 hours. I tried all of the tips I found online for a through cleaning and battery reset. My cure was that I found lots of hair inside the roller brushes- under the yellow cap on thier axle. This was a big power drain. The yellow cap pulls off and the post that it was attached to pulls off. This allows access to the gunk. I did check the other end of the brush rollers. That side does not seem to come apart, but I was able to see inside and it was clean. I also ised a needle to clean out a wad from under each rubber tire. Our Roomba works now.