Zumo robot power

I recently bought a zumo v1.2, and i am using a SainSmart arduino clone. However,the code only works when the robot is plugged into the computer.Also, it worked great for the first hour or so(besides the usb problem), but now the motors will barely turn. do you know what is wrong? thanks.

From your description of the problem, it sounds like you might not be using fresh batteries. Can you try new or recharged batteries to see if it fixes the problem? If it does not, can you try removing the SainSmart board and measuring the voltage on the Vin pin when the Zumo is turned on? Also, did you get an assembled or kit version of the Zumo robot for Arduino, v1.2?


I think problem is in motor. So,I recommend the 50:1 or 100:1 HP motors for use with this chassis.

I have the assembled version. The right motor is not working at all, but the left one is fine. should I be using rechargeable batteries? I will try replacing the batteries and measuring the voltage.thank you.

We generally recommend NiMH batteries for robotic applications since Alkaline batteries have a higher drop in capacity as the current draw increases. This means that applications that require more current (e.g. several hundred milliamps or so) like the Zumo, NiMH cells tend to last longer. You might find the information in the “Understanding battery capacity: Ah is not A” blog post helpful; it covers some differences between Alkaline and NiMH batteries in more detail.

Also, I noticed that the description of your problems seems to have changed since your first post, which made it sound like both motors barely turned and the Arduino-compatible board you are using wasn’t properly getting powered form the Zumo. Has something changed between your first post and your more recent one?


The code still only works when the robot is plugged into the computer through the arduino’s programming port. The motors are not barely working, but one works fine and the other is not working at all. Sorry for the confusion.

Thank you for the clarification. It is strange that the shield is not powering your Arduino-compatible board. I think we should find out what is causing this before moving on to troubleshooting the motor, just in case the power issue is interfering with the signal controlling the motors. Did you ever replace the batteries and measure the voltage on the VIN pin? If you have another power source available, you might also try removing the Zumo shield from your system and making sure your SainSmart board works as expected when powered directly through VIN with around 7.5V.