I'm not going to search through your old posts, but battery is new, so good, but is it run regularly. Has it been stood or doing short journeys so it could be getting low on charge.
What's the mileage? When was the last time it had an oil change, air filter change, spark plugs?
My car is on 45k and fair enough it's a 57 plate, but the only time for me personally that it's needed a few more turnovers was when the battery was very nearly done, as above. Check the regulars as I've suggested, then get the battery checked again to see that it has charge.
All is assuming you have no engine management lights, i.e. running a decat without a remap etc.