Have signum cdti and it would randomly cut out at islands or traffic lights, no particular reason for it no excessive electric being used no thrashing no dordling jus on normal driving. Went and purchased a new battery as turns out the 1 fitted wasn't a diesel battery and wasn't powerful enough. Now runs like a dream no cutting out (touch wood).... Jus the malfunction indicator light dreaded p0650 code too try sort now along with regen!