We suffered a dog poo-pacalypse with our Roomba last December. In cleaning him up, I must have gotten his original battery wet because it wouldn't hold a charge and just beeped uselessly on the charger. We did a lot of research on what replacement battery to purchase and settled on this one after considering reviews over time. It's been several weeks since we installed the battery-- it seemed like it might be too big, but after screwing the battery cover down, it fit perfectly-- and the Roomba has worked like new since then. I'm really glad to have my floors more or less swept. The Roomba runs for about 2 hours in the morning hours, and doesn't have to stop early because it ran out of battery. We haven't ever had that problem, as a matter of fact.