Review on Tenergy 14.4V 3850mAh NiMH Battery for iRobot Roomba 900/800/700/600/500 Series - Extended Life 🔋 1000 Cycles, Vacuum Replacement Batteries with Bonus: 4 Side Brushes & 1 Brush Cleaning Tool by Sierra Stewart

Bought a Roomba 960 in 2018 as a Christmas present. The original battery could never fill an entire house without recharging. It started out lasting about 45 minutes. I found it takes about 1.5 hours to complete building the entire house. We replaced the original battery in the first half of May 2021. Back then, the original battery life was reduced to around 25 minutes, which will last around 6.5 hours. to complete the whole house, but in most cases Roomba died before he could return to the charger. This replacement battery was easy to install and you could feel the difference immediately. After an initial full charge, Roomba ran the entire house on a single charge. This replacement battery had more capacity than the original battery, so I was expecting a longer run time. It was also about a third the cost of a higher capacity OEM battery (now less than a third). I waited 6 months before leaving a review as I wanted to see how it held up. Our Roomba runs every day (when the bin is empty) and on about 3 occasions it walks around the house without charging. The rest of the time it will charge and then run for about ten minutes to complete the job. We had some charging issues, but they were caused by dirty contacts and not a battery issue. I don't see any reason for that at the moment. The battery doesn't last a year or two before it needs to be replaced and as long as this replacement battery is still available I would buy it again.