What is the range of the battery, how can I charge it and how long does charging need?
The range of the vehicle is 80mi - at moderate speed. You should not drive it to 0% battery.
The car comes with a 120V charger that you can plug in at any standard plug at home. With a 20 amp circuit you can fully charge the car over night.
You can also use all public level 1 or 2 chargers. This is much faster - round about 3 hours.
Do I need to return the car at 100% battery
No, it is OK if the battery is low, but never discharge it below 10%.
Dietmar is very kind and thoughtful, he prepared everything before he handle the car to you.
The BMW i3 is cute and nice. Saving quite some time commuting on car pool lane during peak hours. There are tons of EV charging stations around the town with easy to set up mobile app activation (e.g Charge Point), so no need to worry about charging. Dietmar is a very nice and helpful owner. Highly recommended!