Iām pretty certain they either miss-quoted that 15 mins charge from solar plus regenerative driving to get 300 kms additional range or the video suffered from bad editing.
In the entire 1200km test drive they quoted the regeneration system only amounted to a couple of kw. Impressive, I agree, but not 300km extension of range. Closer to 20km at the impressively efficient 8.5 kW per 100km.
To add 300km range, by driving in sunlight, is purely impossible. Otherwise the EQXX, on a sunny day, would be a perpetual motion machine.
Driving at its max speed of 140km/hr it would only cover 35 kms in 15 minutes, and so, based on that calc, would have 265km of spare capacity, by solar and regenerative charging alone. It absolutely makes no sense.
And anyway - as a weight saving measure: ā
The solar panels only convert into 12V power and donāt go to the 900 Volt drive systemā.
https://electrek.co/2022/07/25/mercedes-eqxx-drive/
So the solar panels only help with ancillaries that are run off the 12V standard car battery. The solar panels, thusly configured, are merely a gimmick and only extend the range by reducing the draw down for ancillary power needs. The 12V system probably runs the lights, the radio, and power operated devices such as windows, seats etc.
It is even debatable whether or not the solar panels are even of any benefit at all as the small power generation probably doesnāt offset the additional weight, nor the huge expense to repair simple scratches.
I can only accept that some bad (intentional?) video editing caused the confusion. They probably were talking about 15 minutes connected to a super fast charger, but bad editing cut that into talk about the solar panels and regenerative system.