Power supply L298N and DC motors

Hi all, I'm getting some troubble and I think someone can help me. This weekend I built my first robot and it's working, but only if the bridges and the dc motors are power supplied with a wall plug adapter. When I use 4AA batteries it doesn't move. Can anyone tell me how to handle this? Maybe with some sort of batteries, like lipo or anything similar? Thanks in advance.

José Coelho

PS: I let some photos of the robot. The first one without the connections between arduino and bridges and without power supplies connected. The second one working but with the breadboard just for debugging and powered from the wall.

Is your wall wart 6V? That is not enough to drive an arduino through the power jack. Measure the battries under load with a meter. What is the voltage of your wall wart?

The arduino is powered by a 9v battery. The wall wart has a range from 0 to 12V, it was on 6V. The batteries without anything else connected give 5.89V. But when under load, each motor only gets arround 0.40V.

The batteries without anything else connected give 5.89V.

So what is the battery voltage when the motors are supposed to be on? Sounds like they can not provide enough current.

When the motors should be on, it goes down to 3.8 ~ 4V. I made some measures and all values were between that 2 values.

josecoelho: When the motors should be on, it goes down to 3.8 ~ 4V. I made some measures and all values were between that 2 values.

That means your batteries are flat or they are not big enough to supply enough current.

I tried with some more batteries connected in series (giving arround 12V) and the motors were working just great.