The difference between iRobot Roomba 645 and 650 are as follows.
Roomba 650 vs 645
The iRobot Roomba 645 which is a Sam’s Club exclusive is a similar model to the 630. It has NO on-board scheduling whereas the 650 features the On-Board Scheduling that allows you to preset the cleaning time for Roomba to clean whenever you want.
You can see this difference from the faceplate of the two units.
The iRobot 645 uses the Xlife Extended Life Battery whereas the 650 comes with the Advanced Power System battery.
The running time of these batteries per charge are the same, the Xlife battery however, has a longer overall battery life.
The 645 uses a new easy to remove side brush that has a flat head screw while the Roomba 650 uses the brush with a crosshead screw.
The 650 is more expensive.
The 645 is priced at $329.98 at samsclub.com whereas the 650 is priced at $399.99 at irobot.com
Brush Cleaning Tools
The 645 comes with 2 brush cleaning tools ( 1 round and 1 flat), while the 650 comes with only the flat brush cleaning tool.
The 645 faceplate is in gray color whereas the 650 faceplate is in black color.
If you know other difference between the Roomba 650 and 645, please share below, thanks.