In the last year not used the Exige as much as I should have 
Usually its a couple of weeks between uses but everytime she won’t initially fire up - turns over absolutely fine and free but no sign of a start - put battery on charge for 30 mins and away she goes??
Is the old girl trying to tell me something or what??
Low battery voltage can make starting hard. Due to the length of cable between the battery and starter, voltage drop is high, which can lower the voltage feed to the ECU, making spark during crank and fueling erratic.
Yeah I would say its simply not enough current getting to the ECU when cranking
my MoTeC is a bugger for this… a lot pickier than the stock ECU as it prefers to shut the engine down than try to make do with lower voltage, below which it cannot accurately meter fuel… in a highly tuned race engine, it figures that shutting down is preferable to running lean and screwing the engine before shutting down thereafter. It’s fine, just need to make sure the battery is up to cranking the engine without a decent voltage drop.
As a previously well-known reluctant starter, I’m tempting fate by saying this but the yellow peril has been firing up fine for a while now.
Various suggestions were made when I was having a struggle, including crank sensor(replaced) and that other sensor thingy whose name I forget, that is under the rear offside of the car close to the suspension. The car is kept on a battery conditioner and she had a new battery when I bought her almost five years ago.
But It was only after having a second new coil pack fitted almost 12 months ago that things cleared up.
Fingers crossed that I have not upset the applecart . . .
Good luck, Simon