Almost every day when I get into the car I have to set the clock again, because for a short time the power has failed. Why is that? The battery is fully one of Bosch has cost 200e. I used to never have the problem. It’s only been a few weeks now and it’s annoying because it also erases the driven kilometers. Now I bought such a battery pole protective spray color blue and thus sprayed in the contacts. But it didn’t do anything. What can that be?