My dads scenic had this fault but this was due to the clock issue which they did a recall for. Could be a dodgy earth somewhere? If the engine mount are worn the excess rocking could losen the earth to the batter or cause damage to it.
I had this last year. Crank position sensor was the cause. Symptoms I had was engine would cut out. Display says engage neutral, interior lights come on. Then sometimes it would fire up straight away other times a few hours
Hope this helps.
i had this recently, although it wasnt a complete electrical failure it stopped my engine from starting. Turned out to be an earthing problem somewhere in the engine wiring loom and it all had to be replaced at a cost of £650. Get in touch with renault uk if its low milage/newish car, they usually contribute towards the cost.