IRobot 780 charging problem

  • Problem
    • The Irobot showed Error 5 on it’s display.
    • After measuring the AC adapter, it showed about 22Vdc.
    • The faulty battery show 15.6v after charging the robot.
    • I bought new battery at AliExpress from HERE. It was a battery of 3500mA. The original battery showed mark of 4500mA.
  • Solution
    • After that I took an Irobot from friend and used his battery, 4500mA new battery, and the faulty Irobot worked OK.