battery dyeing and rough idle

astra j 1.4 excite petrol 2011

hello everyone, I have had this issue for about 2 months now, battery dies is left for more than 2 days without driving, has a rough idle and when I turns the lights on it shakes for a second as if the car is delayed in sending more power to run the lights. but when i put the aircon on it doesn't rough idle anymore and is very smooth.

car runs fine when driving but when at lights or a stand still it feels like the car is idling to low and rumbles slightly. the car is idling where it should be on the gauge. I have done a parasitic draw test with no luck, multi meter is saying 0.0amps. changed the alternator, coil pack, spark glugs, idle control valve, tested all the earths I can find on the car and all seem ok.

kind of out of ideas now and was wondering if any one had any other suggestions to try. any ideas would be greatly appreciated.