On the Scooba 450, error 1 is associated with the red light to the left of the CLEAN button flashing.

The error is not common, but occurs approximately after a year or more of prolonged use or after a long period of inactivity of the Scooba 450.

The message says "I have encountered error 1. Contact IRobot technical  support".

Here's what to do to resolve the error:

In 99% of cases, the error is resolved by changing the battery or cleaning the contacts.

Rarely, it may happen that the contacts of the power connector 

are also oxidized. Here's what to do to resolve the error:

In 99% of cases, the error is resolved by changing the battery or cleaning the contacts.

Rarely, it may happen that the contacts of the power connector are also oxidized. Spray a product such as CRC antioxidant.

Rarely, it may happen that the internal charging circuit of the Scooba 450 has a fault.

In this case In this case call technical support