My D6 battery light quit working but the battery was 3 years old - I got a new battery and it would work (came changed) but the charger LEDs would not light. Turns out the cord got pinched behind the bracket. I redid the layout and it started working but the old battery would not light up all day on the charger so it is just dead. The new D6 also will shutoff after it is running for a while but not a lot. I found some dust matting in the brush head so I think that was a warning sign to clean it. Have to take a flat screwdriver and twist the grey button about 1/4 turn to unlock/remove the plate on the brush head to get at the clog.
My first Dyson still cuts out so much it is really unusable. The adapter barrel and the battery are slight different that the newer D6 I got so are not interchangeable. Sigh...