"The Federal Association of Energy and Water Management (BDEW) collects and publishes every six months the growth and inventory of the publicly accessible charging infrastructure in Germany. All aspects of customer-friendly charging are surveyed here (location data, opening hours, methods of authentication and payment, charging services and connector types)". (NPE 2015).
The data collected for the BDEW charging station register includes reports from energy companies and other market players such as car park and parking lot operators, supermarkets and hotels. The charging station register can be interactively surveyed, but unfortunately the data is not openly available.
Since 2013, LEMnet Europe e. V. has been operating an extensive and high-quality database of electric charging stations for electric vehicles (http://www.lemnet.org/map). LEMnet is suitable for searching for the right charging infrastructure. The picture shows the situation in Mecklenburg-Western Pomerania and neighbouring regions.
But also in OpenStreetMap you can find charging stations, in OpenChargeMap even more. In the exercise on the national situation of the charging infrastructure you will find a more comprehensive overview of providers of web maps and data on charging stations.
Take a look around the pages of Lemnet. Look for other websites that offer data on charging stations.
Why do the numbers between the offers differ so much?