Matt White pointed out it was probably the big capacitor on the Novak! You're right though matt, I've revived NiMh cells in the past when I've left them hooked up - but there's no chance I'm going to risk reviving the LiPo
So vickys car was a bit slow at worksop the other day - still, it all worked out well in the end as she beat 4 people! yay.