Solar starter aid
Rolling with the engine turned off, but I forgot to turn off the lights after the exit Salzburg Mitte, some hundred meters Münchner Bundesstrasse
and waiting at a traffic light was enough for the 8.5 year old starter battery to show its age weakness. Nothing worked anymore. At first I thought, luckily, it happened right next to a gas station, but they couldn't or didn't want to help at the gas station.
Doing what? Luckily it was a very sunny November day, luckily the car had stopped at a sunny place. Despite the low sun, the 50 Watt photovoltaic delivered 1.63 A charging current. After half an hour the starter battery was fit to start the engine again.