I would imagine you would have to sit for a *long* time before there is enough charge to crank the starter - and if you crank too early or it has trouble catching you are back at square 1.

Last time I left my lights on (in the cop car, before I rewired the chimes) my mum brought her 998cc Nissan Micra and some piddly jump leads - as you can imagine it had no chance jumping a 350 V8!

I took the battery home and came back the next morning - it was in Winchester which is pretty safe on the whole. I now have a good set of tools and beefy jumpleads in *both* my cars.

Gareth