It may not be the CMOS battery as the following post describes. If you used an air compressor, that is quite a bit of pressure. Is it possible that the BIOS chip is loose or damaged or the battery contacts are slightly bent? This error can also be caused by a problem with the motherboard. Also not sure how long you left the battery out of the socket. Leave the battery out for at least 15 minutes (Intel recommends 30 minutes).