Huge voltage drops and hot battery wires
My team and i are preparing for an offseason competition with our 2018 robot and bumped into some problems with the electrical system. The robot is drawing too much voltage from the battery and also heating the battery wires up.
We've tried trouble shooting the problem by disconnecting the compressor, because we have a minor leak in the pneumatic system, but that's another fix for another day. This decreased the load on the battery, but we could only drive for about 30 seconds before dropping to 5 volts.
When we went to disconnect the battery, we've discovered the battery wire was burning hot. The wire that connects the main power switch wasn't warm at all. Also, there were no other warm wires on the robot.
We've tried 7 different batteries from different years including new ones, but they started to dip below 5-6 volts about 30 seconds after driving around only with the drive train.
There were no modifications to the robot before we went on summer break. Before that, we had no problems with it.
I just wanted to ask for some ideas what the problem could be, so when we go back to fix the robot Monday, we have a place to start.