limey2.. your hub looks just like mine, as does the battery bag.. I got the same one thrown in.
A couple of things -
The main battery wire and fuse (glass fuse type) that came with mine (36v 750w model) actually burnt right through and snapped on the negative wire at the battery that came with the wheel kit. The standard battery wires that came were just not upto the job when on my 3x12v 12ah SLAs
I also upgraded the standard glass fuse and plastic fuse holder that it came with, as the plastic fuse holder had started to melt, I upgraded all wiring to the batteries, and used the blade type fuses and blade holder, 30 amp blade fuse holders and fuses were easy to find on ebay.
Another note with the battery bag, after 3 days the velcrow straps on the underside of the bag actually snapped off that were wrapped around the rear rack, and came appart at the stiching - my 3 SLA's are about 12kg in total and the bag stitching could just not take the weight.
Just a few things to consider, mainly the battery wires, they could have easily caused a fire as I have foam padding around the batteries.