I'm just starting to delve into robotics and electronics, and my first project was building a small Arduino collision-avoidance robot with a ultrasonic range finder, one servo and two DC motors.

Right now I'm using a 6 V battery pack to power both DC motors, another 6 V just for the servo, and a 9 V battery for the Arduino.

But I'm in doubt if the power supply for the DC motors is enough. I'm using an L293D IC to control both motors, but the robot can barely move under load (and the total weight of the robot is not that much. I already reduced all the weight I could). So, how much power, typically, I should supply for the L293D to control those motors?

  • 4
    As has been covered many times here and on electronics.stackexchnge, the L293/L298 are antiquated devices with high internal losses, meaning you essentially loose one cell in your battery pack just to heating up the chip. Ideally you would replace this with an FET driver, otherwise you will need to add at least another cell to the battery pack. Commented Jun 4, 2016 at 19:34
  • Is a FET a IC, like the L293D?
    – Vinicius
    Commented Jun 4, 2016 at 21:51
  • The L293 is bipolar IC, not an FET IC. TB6612FNG is a small FET dual H bridge used with more success on some newer motor shield type offerings. There are other choices discussed on electronics.stackexchange as well. Commented Jun 4, 2016 at 22:16
  • Do you know how much power drains your motors? Because we can't help you if you don't give enough infos. Commented Jun 27, 2016 at 15:57
  • I do not know which Arduino you are using but the 9V smoke alarm battery is about the worst choice you can make. You do not have much current available nor a lot of capacity.
    – Gil
    Commented Sep 6, 2022 at 0:58

1 Answer 1


The L293D can handle two motors at a time and as per the data sheet the maximum voltage that you can give to the motor as a supply (on pin 8) is 36 volts.

  • 2
    This is not a valid answer to the original question. The OP knows that he can handle 2 motors with this IC, he does not worry about voltage supported by the IC either. He wants to know what power (or current, if we consider the 6V voltage fixed) he needs to properly make both motors move.
    – jfpoilpret
    Commented Sep 10, 2016 at 8:48

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