Longer battery wires

[Al Skierkiewicz]

Guys,
What I am trying to get you to think about is this...
1. All robot current flows through the #6 wire from battery to PDP.
2. Any resistance in that loop will drop voltage at a predictable value.
3. Worst case voltage drop will affect the voltage available for other systems.
4. The RoboRio is the most important followed by the radio for keeping available voltage as high as possible.
5. Regardless of your design, all motors draw stall current when starting.
6. Brownout voltage doesn't matter to motors if the control system has already died.
7. The voltage dips you see in your logs are real as measured by the RoboRio. This confuses most people but those dips do occur. The log is not lying to you. WildStang did some extensive research into this more than ten years ago. We were able to compare video and voltage data to show that certain behavior leads to voltage drops. We had developed an app for Blackberrry at that time to put it all together and generate warning messages for our drivers at that time.

Yes, motors will draw less current at a lower battery terminal voltage but they will also likely stay at near stall longer as drivers push the throttles to max to get the robot to move as they want. Turns will also push the current to extremes if you have a lot of tires or tank treads on the ground.