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 Carrie Porter

Ordered at this price. It's been 9 months and it's not charging anymore. If you look at the charging process for 1.5 hours, the charging time is almost 4 hours. And it hasn't changed since day one. I would avoid this and use Roomba lithium-ion batteries. Update: I changed 1 to 3 stars. The battery is not my problem. The base charger is defective. This gives loading error 15 if someone else has problems. I bought another iRobot base and it's working fine again. The battery still doesn't last very long and spends far more time charging than sweeping.