Smell from battery

[growler2058]

What Kiwi said ^^^^^

Won't be the A/C, well, 99% it won't be the A/C unless someone put a egg down your vent.

If you have a real good smart charger you may get the battery back but in this day and age the plates etc are so thin that if you boil a cell it usually warps the bejesus out of them.

Take it out, wash out the tray as suggested, check the cells and top up as req'd and put it on a smart charger in "recondition" mode.
If it comes good awesome but check what the Alternator voltage is when you put a battery back in the Car.
Should be 13.8 min to 14.7 max, usually you will see around 14.0 to 14.5 ish

Ive been in a vehicle that with the aircon on it smelt like dirty arse