Servomotors power supply

Good afternoon

I have been designing a robotic arm with 5 servomotors.

I have been testing each one separately and when I feed the motor via arduino board It works perfectly.

If I feed the motor via protoboard with the power of arduino board, some of them start behaveing bad.

If I feed the motors via protoboard with external power supply of 3 doble A batteries it happens the same, bad behaviors .

What could be the solution?

Is there any external power supply of 5V that can give me the same amperage of arduino or higher?

Thankyou in advance

AA batteries 3 X 1.5V = 4.5V your Servos probably need 6VDC.

There are many many 5V and 6V motors available, use Google.

What is the electrical ratings for your servos?

AA batteries are unlikely to provide enough current for 5 servos, they may need around 5A peak all together. Servos are very power hungry.