Power circuit for Ultimate 2.0 Kit


#1

Hi,
I just got the Ultimate 2.0 Kit and I’m really not interested in using the 6AA battery setup. I’m planning to use a rechargable battery. I know this was discussed before in older threads

Power supply options for Ultimate 2.0
Help deciding on a good battery

But the threads suggest 7.2V battery besides the included power pack providing 9V (6x1.5V from AA=9V). Which is acceptable because the output from an Arduino is only 5V and the MegaPi being an Arduino derivative should only be able to provide 5V (It’s even mentioned on the board). So whatever the input we provide to the board, it’s still going to provide 5V to the components connected to it. This is fine for sensors but it undervolts the motors preventing them from operating at their full efficiency.

I’ve decided to make a circuit to power the motors and the board separately each at 9V. The encoders and sensors will still be attached to the MegaPi.

Instead of buying a Li-Po battery, I’ve decided to buy a power bank to make the recharging easier and it is much safer as well. I found fast charging power banks can provide 5V-2A or 9V-2A depending on the device connected. Manufacturers market it as “smart switch” between modes. I am not sure how to draw that 9V.

I hope someone could help me with suggestions on the external circuit and power draw from the power bank. Also, does someone know the technical specifications of the motors other than the speed and voltage?