Thanks. Battery sounds great though.

OP. Out of interest, if you keep turning the engine over does it eventually start?

My son has the same car as me, an Astra 1.0T (obviously different engine to yours). His is a very early model whilst mine is about 9 months newer. First start of the day (not temperature dependent) involves several seconds of turning over without any sign of it firing, then it starts and runs perfectly. Just as it does for the rest of the day. Battery is fine as start stop works and it's always done it in the 4 years he's had it. Mine starts immediately always. Astra forum suggestion is it's to allow oil pressure to build first as other early builds reportedly do the same. Don't know how true the theory is.