I bought a VR 408 two weeks ago, the assembly with my kids was great, but the first tests…very disappointing. The robot seems to have not enough energy to move on his own. So I bought new, expensive batteries (duracell). But even with these fresh and top quality batteries, our VR408 can’t move a leg without being plug with the USB wire on a computer (to provide energy). Do you have any solution, please? Should I send my Allbot to your post sales department?