$50 robot battery question

[RiffRaff]

First of all, Thank You for all the terrific tutorials!  I am learning a lot.

As far as the battery set up for the $50 robot, is a 4 pack of AA batteries (6v) sufficient, or would I need to add a 9v battery?

Thanks,

Kirk

[Razor Concepts]

4 AAs are just fine 

[RiffRaff]

Thank you!