I would also like to hear from "slee" about his experience with his Rize City. I received mine a week ago and have thoroughly enjoyed a few rides of about 55 kilometers in total (I have not been a regular bike rider, and this is my first e-bike, so am taking it easy, since I am a senior!). Assembling the bike was pretty simple, although I found that it was easier to use my own tools, rather than the multi-tool that Rize included. I was also pleasantly surprised to learn that the bike came with quick releases for the front wheel and seat post - I don't believe this was mentioned in the description of the City bike on the Rize site. I did have to tighten the seat post after a few rides because the seat post had worked its way to the bottom ( I'me not a big guy at 5'6" and had not noticed during my ride). I also moved the controller on the left side of the handlebar a bit more to the right, since I found that my thumb would sometimes brush against the PAS up and down pads and change the settings when using the throttle.
I have been doing a fair bit of reading about e-bikes in general and battery charging in particular on the EBR forums and other online sites and have reached the following conclusions - I would welcome any comments, additions or corrections:
1. If you want to maximize the distance travelled or are suffering from "distance anxiety", and don't want to pedal a bit harder, then charge the battery to 100% of capacity after every ride. No harm will come to the battery in doing this, but the downside is that it will reduce the number of charging cycles available during the lifetime of the battery.
2. If you are more concerned with maximizing the number of battery charging cycles over its lifetime, then only charge it to about 80% - about 51.5 volts for a 48 volt battery, and try not to let the charge fall below 20% or so.
3. Fully charge the battery at least a few time during the cycling season to balance the cells.
4. Let the battery cool off for about a half hour before starting to charge it.
3. Batteries do not appreciate extremes in temperature, particulary if it is in a hot environment.
4. If you are attempting to charge the battery to 100% you may have to charge it longer than the advertised charge time to reach full capacity. For example, after a 30 kilometer ride yesterday my 48 volt 13 ah battery was down to about 50% and showing 46.8 volts on my multimeter. It took about 3.5 hours to reach 100% (54.3 volts), at which point the 3 amp Rize charger green light came on and the fan stopped working.
5. Try not to leave the battery at a 100% charge for longer than a few days and give it a 50-70% charge if storing for an extended period - you may have to top the battery up a few times during that storage period to maintain a 50-70% charge.
Since I am a retired senior rider, using the bike for recreation only and not really interested in marathon rides, I will probably go with point number 2 above for battery charging.
The "E-bike Battery Guide" section in the EBR general forums provides a lot of great info if you want to 'get into the weeds' on this subject.
BTW my experience with communicating with the Rize staff has been very positive, with answers to my emailed questions within a day or two and quick phone pickup or response to messages.
I was lucky as they were having a fire sale on spark branded bikes to start rize bike brand so I got 500 off the price and I got them to throw in the nice rack bag that was on it for free 
