I purchased the Developer kit in hopes of trying out the Teddy Ruxpin project. I have the EZB v4 powered by the 6 rechargeable batteries like recommended; however, if I attach a servo to it, it will reboot if the servo attempts to move more that a few degrees. Is the rechargeable batteries only powerful enough to turn on the EZB? Do I need something else to actually run the servos that comes with the kit?