Power problems

I currently have an Arduino UNO connected to a L298N which is then connected to 2 motors. Problem is, only one motor spins at a time, and when it does it is very easy to make it stop by holding it with a hand, and when you let go it doesn't start to spin again. You need to give it a spin with your hand to make it start rotating again.

I think the main problem for this, is the power supply. I had 4 1.5V cells connected in series in a cell holder which outputs 6V, which I connected to the L298N and took the 5V+ output and attached it to the 5V pin on the Arduino board. This made me think that the motors weren't getting enough power so I made the 6V go only to the L298N module and had a seperate 9V battery for the Arduino board. Turns out, it didn't really make a difference.

So, is 6V too low for two motors? These are the motors by the way. I'm really starting out in electronics so any help would be appreciated!

Here's the code:

// motor one
int enA = 10;
int in1 = 9;
int in2 = 8;
// motor two
int enB = 5;
int in3 = 7;
int in4 = 6;

void setup() {
  // put your setup code here, to run once:

  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);

void loop() {
  // put your main code here, to run repeatedly:

  // Motor A
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);

  analogWrite(enA, 255);

  //Motor B
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);

  analogWrite(enB, 255);


A diagram showing your wiring would really help!


6V should drive the motor just fine. It is rated for 4.5V, but are you really getting 6V out of your batteries? measure the voltage at the L298N while you hold the motor in the stall condition.

Do you have a sense resistor on the low side of the bridge? What value? that can reduce the voltage across the motor.

The (old technology) L298N has a dropout voltage of about 2volt in H-bridge mode at that motor current. To compensate for that, supply voltage should be about 2volt higher than motor voltage. Make sure batteries can keep up with motor current. Leo..

Here's the schematic: |500x368

Why are there two pairs of wires from the battery holder?

Are you sure you are feeding 6v to the L298? I suspect it is only 3v.


It's just the way Fritzing works, there wasn't a four AA battery holder and so I used 2 two AA battery holders. It is actually just a 4 AA battery holder with only two wires.

Any help?

ahk1221: Any help?

You have not answered about the battery voltage under load! So, how can anyone help.


Figured it out. It was a low voltage problem. Thanks for the help!