Came back from holiday a few days ago and car has not started like normal but guessed it was due to it sitting around for nearly 2 weeks, Yesterday after a a 20 mins drive I parked up then had to move the car but it was dead, went and got a new battery from Halfords today but on the way back i had the battery light coming on and the dash needles dropping off and back up, the car also died a few miles from home, changed the battery on the road side and drove it home with the battery light, on also read the voltage, the new battery was about 12.7 (i think) but with the car running it was 12.1 so guessing the alternator is fubbered????
Also..
How long do you think I could drive like this, (I'm thinking of to the garage about 20 mins away!)
I have a sub in the boot, do I need a 120A alternator, or will 100A be ok???
Any help is much appreciated!!!