Coming to us via eGear.com is this how to video that shows range mode (Range Plus) activation on the Mercedes-Benz B-Class Electric Drive.
Short video explaining how to active the Range Plus option in the Mercedes B-Class Electric Drive. Range Plus increases the range from 200 to 240 km.
eGear offers a bit of a more thorough explanation of Range Plus by stating:
You would think that Range Plus adds extra batteries but that’s not the case. Normally the B Electric Drive enables 77% of its 36 kWh battery pack which corresponds to 28 kWh usable capacity. By enabling Range Plus you can use 93% of the pack which equates to 33.5 kWh.
For more detail on Range Plus, check out eGear's article here. We should note that Mercedes has decided to make the "Range Package" standard on new 2015 editions of the B-Class ED; for the inaugural 2014 model is was a premium option ($600 in US, upwards of 900 Euro internationally).