Voltage source for servos

Good, I have observed by pages and videos that to move my 6 mg996r servos it is better to use an external voltage source. I am new in the arduino world and I have read that a source with 5V and 6A would be necessary but I do not know where i can find it and if it would really work. How do I really know what volts and amps I need? With a 4-cell battery, would that be enough?

Thanks

It depends on a number of factors: how many servos are moving at a time, how far, how fast.

i’m making a robotic arm 6 dof, so i want to move all 6

That high torque servo has a stall current of 2.5 Amperes, which it draws every time it starts.

If all 6 servos will be moving at once, buy a power supply capable of delivering 5 to 6V at more than 12 Amperes.

That is, 60 to 72 Watts.