One of the advantages of using components that others are using is that you can use their wiring diagram and make it your own. I looked at a lot of ME1003/AXE7245 system diagrams before I drew my own.
I also read forum comments on schematics that were submitted for review. This was very helpful as most people were making the same mistakes, so I got a feel for what to avoid. I did not draw the 12V system at this point.
My schematic of the drive system ended up like this:
Follow these pointers to avoid the most common errors:
1. Don’t put any component between the battery and main fuse.
2. Fuse each component circuit with a fuse sized just a bit over the normal load.
3. Use a flyback diode on contactor and relay coils.
4. Use components that are rated for the voltage and current they will experience. The switches on the handlebar of your motorcycle are not rated for pack voltage.
5. If you disregard (4.), think through the failure you are inducing and expect it to happen.
6. Have a means of disabling the drive path in an emergency without turning off your lights.
7. Read the manuals and wiring diagrams that come with your equipment. Heed the diagram and notes unless you have good reason to do otherwise.
After you create your diagram, stare at it and imagine what will happen if a component fails. Switches can fail on or off. Electronics can short circuit. A permanent magnet DC motor controller can fail with full power on. Relays and contactors can weld (stick closed) or fail to close. Imagine yourself handling each situation: What will be the indication? What will you do? Decide whether you have enough safety features built in to satisfy your comfort level.
Next: Balance the Batteries