The 7.4kW water-cooled, on board charger gives recharging rates on an AC household wall box of about 11 hours, although at a DC quick-charge station you'll get an 80 per cent charge in 40 minutes.
The Mercedes ‘me’ phone app is a bit gimmicky, but one useful function is that it will allow the use of a wide range of different recharging stations (of which Europe has about 200) without having to download apps, arrange finance and so on. Dealing with recharging companies can be a headache for electric car owners so this is a major boon.
I used the Ionity 150kW charger en route from Oslo to the Norwegian fiords; the car's internal screens correctly identified the pump, arranged the finance and I plugged in with the thick, heavy cable. Charging at a steady 89kW, it took about 25 minutes for half a charge. The app also gives you details of the battery charge and allows you to remotely preheat or cool the cabin while the car is still tethered to a charge cable.
It can be a nuisance, though. With US prosecutors looking at the monitoring habits of such voice-controlled systems, the Mercedes me system is clearly listening as it butts into conversations when it thinks it has heard the word Mercedes ('monster, mercantile, mercy') and worryingly over riding the navigation display.
Safety systems are comprehensive, including emergency braking, pedestrian and bicycle recognition, lane keeping and blind-spot monitoring. Some of it is part of the £1,695 Driver Assistance package, however, and only available with more expensive trim packs.