Here is my finished electrically converted Cross City 4. It has the 200W front mini-motor and the new 9Ah Panasonic tube battery. I just took it for a 21 km ride and it performed very well. I averaged 21.8 km/h, using power for all the uphill and acceleration. The battery is still showing 75% and I felt pretty fresh for an old dude without much fitness. I was pleased that there is very little rolling resistance from the motor and it is quite fast enough for my needs. I fitted a Spanninga 36V front light and wired this up to the tube battery and that works quite well.
Thanks for all your help with the bikes Matthew and I wish you every success.