Two contactors

 
Here we see two contactors. (Electrically powered switches.) Originally I had just one on the negative end of the pack. Adding a second one for the positive end seemed a good idea from a safety point of view but finding the space was difficult. You can just see it below the big wires going to the controller. It is reversed with the connections on the right in order to keep the positive cables away from the negative. More separation would be better.

The other black thing sharing the mount with the upper contactor is a fuse holder. There is a BIG fuse under it. The shunt for the ampmeter is attached to the firewall below the fuse. The wire from the negative end of the pack goes to the fuse which connects to the shunt which connects to the upper contactor which connects to the controller and the motor. The battery in this picture is the positive end of the pack. It connects to the lower contactor which connects to the controller on the right in this picture. The center connection on the controller is the positive to the motor. The charger is connected to the upper contactor and the battery terminal.