One battery for all!? Could that be the problem?

Look at the video. I connect a 11.1V lipo for all the devices include all relays, lights and Arduino. I am not sure if this is a good idea or I should seprate the power source. If so, what's the best setting?? All lights are base on 12V and the motors are 24V and they have their own power source so I am not worry about it. I have use the servos instead just to show the power(PWM?) seems getting low even when I have my control in full speed and Arduino end up reset by itself. After few second it truns back on but slow down again and so on...

Anyone know what did I do wrong?

(Sorry for my bad English :P)

https://www.youtube.com/watch?v=B2nyKOmKZ6U

Nevermind, problem solved!

Nevermind, problem solved! Ground wire issue.