This might be a coincidence, but I'm posting here in case it's something obvious.

I have a 2008 R55 with 14000 miles on it. I recently got the battery change at Sears (the original battery lasted me almost 10 years). My car doesn't seem to have an IBS (there's nothing coming off of the negative terminal) so I didn't think I needed to reset anything). After the battery change, when I drove the car, I noticed a strange whirling sound that reminded me of the movement of liquids and then I also noticed that only warm air is coming out of the vent, even when I have the temperature set to the coldest setting.

I checked all the relevant fuses and they are all fine. I'm not sure if I'm supposed to do anything else after a battery change (since it's my first in 10 years), and whether not doing it would affect the A/C.

Thanks for any help.

 

as you said, it could be just a coincident. water movement could be caused by air pockets in the cooling system! as for the AC, just charge it up and see if that cures the issue.