Hi all, update on this. Appears it was a battery issue. Left it charging for 3 days and then went to fire it up. After riding about 100 metres the lights went out. I've got a lithium battery on mine not not sure if the extended period sat in the garage without the trickle charger connected must have sapped the battery a bit. Been out on it twice now and hopefully that'll be the end of it. Will keep it trickle charged going forward (on a timer) next time its going to be off road for a period.
Glad to hear it's sorted and feeling really smug I was right about it sounding battery related, it doesn't happen very often
