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First let me state that I am a novice when it comes to cars im trying to learn and Was really hoping someone can guide me in the right direction. Okay I left my audi sitting without starting it for about 3 months and yesterday i try and start it and it was a no go, wouldnt even turn on lights nothing and key got stuck in ignition. SO I use the spare key to open trunk to try and jump the car and when i did that everything lite up air suspension lights etc... then i checked the battery level from the mmi it said i had 20% power so i let charge a little,cables are still connected mind you, and when i tried to start car all it did was make a clicking sound so i stopped. I let it charge to 100%, as the mmi read, and tried to start again, cable still connected, and the same thing happen. So when I took the cables off, the car wouldnt even turn on like it was dead again no power or anything. I was wondering what yall think the problem may be so i can try my hand in fixing it, and if i need a new battery is it a simple buy one and replace.

Thanks you guys in advance for any help

Bangerla

Bad battery, replace it.