I would like to control 4 micros servos with an arduino board. I have found a useful tutorial in which he connects the 4 servos to a 9V battery. I have now rebuilt this circuit in a programme and it tells me that the voltage is too high and the servos will break. However, this circuit worked in the video. Is the circuit good or do I still need a resistor or another solution? thanks in advance for any answer 
It depends.
Check the voltage specification of the servos you bought. If they're part of a jumble-kit, good luck.
To answer your question in the topic line, "yes".
Wiring four servos to a 9V battery probably doesn't damage the servos, because the battery is so overloaded, it's output is very very low, and it won't survive long. Connecting only one servo, you have a much higher risk of damaging the servo by overvoltage, but even then, the battery won't survive long because a single servo's operating current is still way higher than what a smoke alarm battery is designed for.
HTH
Oh ok thanks the operating voltage of the servos I will buy is 4.8 to 6 volts. Should I rather use 3 AA batteries?
Depends on the voltages - rechargeable, standard alkaline, ??
Ideally, measure the voltage of 3 or 4 fresh batteries, add up the voltages, and decide that way. Data always beats no data.
Hello, I copied a circuit from online and gave it to you. I have used the same code, but it does not work for me. Why? I only used one motor and therefore did not connect ENA, IN1 and IN2 at all.
int motor1pin1 = 2;
int motor1pin2 = 3;
void setup() {
// put your setup code here, to run once:
pinMode(motor1pin1, OUTPUT);
pinMode(motor1pin2, OUTPUT);
pinMode(9, OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
//Controlling speed (0 = off and 255 = max speed):
analogWrite(9, 100); //ENA pin
//Controlling spin direction of motors:
digitalWrite(motor1pin1, HIGH);
digitalWrite(motor1pin2, LOW);
delay(1000);
digitalWrite(motor1pin1, LOW);
digitalWrite(motor1pin2, HIGH);
delay(1000);
}
how do you power driver module?
are you really using this 9V battery for the motor?
the arduino is not powered 
I supply the arduino with power from the cable I use to upload code
what about the motor ?
those 9V batteries 
are made for smoke detectors. They don't provide much current, and will be depleted pretty quickly if you are demanding.
Thank you. However, I am still wondering why this did not work at all because in the video a 9v battery was also used there it worked
do you have a link to the video? did that work for a long time?
You are using the wrong pins in your code.
Use pins 4,5 for direction an 10 for speed
But they used a new battery!
Thank you, I have changed the code but it still does not work
Do you know your motor power requirement? Do you see any writing on the motor body? Something like "6VDC"?
- Show us good images of your ‘actual’ wiring.
I have changed the code but it still does not work
Then you have a wiring error or a dead battery or you are not using the same exact motor they used in the video.
Remove the propeller.
A 6xAA battery pack would be a vast improvement over the smoke alarm battery.
