Overall: Good solution if you can't fit a bottle mount pack.
Lack of clear assembly instructions made the installation harder than it needed to be.
Mount the battery sled into the rack first.
The surplus nylon-locking nuts in the Power lead pack are (I assume) to replace the hex nuts to mount the battery sled more securely.
Bend the top rack arms and lugs to fit so pressure on the frame fixings is minimised.
The on-off switch and charge port are poorly positioned underneath at the rear where water/road grime will bombard them.
LED lighting is a neat touch.