Cheers Doughboy, yes it does suffer from short trip syndrome, when it came on I took it out for a decent blast for about 45 mins and didn't see the next time I started it up but it still sounds a bit laboured on crank (not to be confused with long crank, more slow)
Think I will still top it up given it will be used even less in the Winter - though it might get lucky with a 6hr round trip to Birmingham next week