underwader

I parked my 2009 Q7 on the road, when I went to open the doors nothing happened! Remote batteries good! I see the instrument warning light illuminated very dimly! I know the battery is stone dead!!! My issue is the key cyl lock hasn't worked in years no I'm stuck outside and can't even place on charge because hood is closed!! Does anyone know if a slim Jim with work to unlock door? Or of a battery positive point that I can access from under the vehicle? HELP