The battery of the 545e is the same size as that of the 530e, namely 12 kWh (gross). The electric motor itself is not more powerful either, but those who are able to resist the temptation to constantly floor the accelerator can accelerate to 140 km/h without waking up the six-cylinder. BMW claims an electric driving range of 54 to 57 km according to the WLTP cycle, depending on the chosen equipment.
When you activate the navigation, the 545e proactively recovers braking energy, taking into account bends, inclines, roundabouts, intersections and so on - as well as the maximum speed allowed. Say you need to turn right in 300 metres. You take your foot off the accelerator and the car recovers maximum braking energy until you reach the ideal speed for the turn. If you drive down a slope and approach a town, it maintains the maximum permitted speed (with a margin of 10 km/h) by alternately recuperating and coasting. Just brilliant.