3.It's bone dry unlike the grit you've been wanting to climb on.
Plenty of head torches
Earlier this year in the dark months I met 2 guys at the terrace area with something similar to this;http://www.dewalt.co.uk/powertools/productdetails/catno/DC022/
Don't you want batteries with more amp hours rather than a higher voltage? In most appliances a higher voltage would increase the power (brightness) rather than the duration of function. If two battery packs are the same size the one with higher voltage will usually run down quicker as it is using the same amount of energy but at a faster rate.
It would be interesting to know if new 12v 2.4ah ones lasted as long as new 18v 2.4ah ones. My guess is they probably would.
Don't fluorescents require less power once they've been started? You can keep them going just in an EM field once they're on, supposedly. Some artist made good use of this, would google but I have to go and churn the IRATA sausage machine.
http://www.pureenergysystems.com/news/exclusive/2004/pylon_ambience/index.htmlApparently so. Just seems you need a crag with electricity pylons running overhead
Bloody sausages! I've had an endless stream of them calling me this week.