Key Fobs Stopped Working

Had this issue, no warning on the dash about low key fob battery. Tried removing the correct fuses and still nothing. Just changed the key fob battery and hey presto it's working perfectly. Next job is to change the battery in the other fob which wouldn't work either.
I've either reset something by changing the battery or it was a massive coincidence that both battery's were on the way out.
Either way it's working now and thought I should share this.

Today, we experienced the same problem. When I pushed "open doors" nothing happened. Then I asked my wife to open the doors with the other key and... nothing happened either.
So, I opened the door with the mechanical key, the alarm was activated and my keyfob worked as before.

I am pretty sure it's not a keyfob problem, but something in the car.
Maybe it was because we had two (2) yes 2 (two) parking tickets in 3 hours time. 50€ for a short town visit