power issues while hooked up to batteries

Projects General Guidance
1

So, i've built a small spider robot (not really a spider, it has 4 legs lol). It is run by an arduino Nano (for now) which is connected to a PCA9685 over I2C for easy controll of the 12 MG995 servos. Now all of this is powered by 2, 30C samsung 18650s in series. There is a pretty heavyduty buck-boost converter which delivers 6.0 V for the servos and the arduino nano should pull directly from the li-ions (~8V). When i have the Nano connected to my pc the robot runs fine. It can walk forward without any issuse but as soon as i try too run it off of battery power directly the buck-boost converter starts to blink and the servos give in, as if there wasnt enough current to power them. i feel like this should work just fine but obviously im doing something wrong, any thoughts?

Thank you

2

MansArildssom:
So, i've built a small spider robot (not really a spider, it has 4 legs lol). It is run by an arduino Nano (for now) which is connected to a PCA9685 over I2C for easy controll of the 12 MG995 servos. Now all of this is powered by 2, 30C samsung 18650s in series. There is a pretty heavyduty buck-boost converter which delivers 6.0 V for the servos and the arduino nano should pull directly from the li-ions (~8V). When i have the Nano connected to my pc the robot runs fine. It can walk forward without any issuse but as soon as i try too run it off of battery power directly the buck-boost converter starts to blink and the servos give in, as if there wasnt enough current to power them. i feel like this should work just fine but obviously im doing something wrong, any thoughts?

Thank you

Did you disconnect the USB cable when you ran from batteries?

Paul

3

Yes, that probably happened a few times.

4

MansArildssom:
Yes, that probably happened a few times.

I think you missed the point Paul was making.

5

I probably did, could you clarify?

6

MansArildssom:
I probably did, could you clarify?

That seems to be a rather common cause of problems lately. Somewhere there was a rational discussion of what trouble it causes and why. Don't have a link to it right now. But it is a perfect way to kill things!

Paul