I keep getting messages that I need to charge battery even after some long runs ie 250 miles in 2 days ,3 days after run battery voltage was 11.7 volts told by dealer this normal anybody else had similar problems.

As it's under warranty id recommend it goes for a diagnostic check to see if any fault codes flag up. 

If it's hybrid it could be an issue with hybrid system or needs a software update. 

The dealer is talking rubbish. Normal voltage in a new car is 12.4 while the engine is off.

Before returning it under guarantee check that you are not leaving any lights on when you exit the car. Have you fitted any extra electrical gadgets such as sat nav, dash cam, phone charger etc?

Thanks for the replies,car 10 months old 4000 miles 1.5 tfsi auto no electrical extras added.

I will monitor battery this week and go from there.