My daughter gave me the subject book, "Electric Motorcycles 2019" by Michah Toll as a father's day present. I just finished reading it. What you have here is something like a book full of electric motorcycle brochures of models that are currently available. It is quite up to date and contains information that became available as late as April 2019. So it is a nice overview of the current market and also contains models that might be available within the next couple of years.
Most of the information presented seems to have been obtained from official factory sources, however the author has also included comments from his personal experience riding some of the bikes along with information obtained from owners of the models, when available. I think the book makes a good resource for historians that might be interested in an overview of the state of the electric motorcycle market in the spring of 2019. For the price, I thought it was a good value and provided several hours of light entertainment.
The only model that I missed in the book was information regarding that European "lady bug" scooter that has been around for a few years and seemed to have been selling fairly well in the EU. Perhaps it is no longer for sale? The book does not mention discontinued brands, such as Mission Motors, Brammo, Victory, Electric Motorsport, Native, etc. Although it does have a page regarding the Alta Redshift EXR, while at the same time mentioning that the company is defunct.
I guess the author has a soft spot for Alta.