I have a 03 Aerio with the original battery @80.000 miles.
Lately it seems to crank a little longer than usuall, not slower just longer. I am wondering if this suggest a weak battery ?
It sounds more like bad fuel than a bad battery. You can check the battery with a simple voltmeter. Expect anywhere from 12.2 (cold) to 12.6 VDC (hot). Temperatures refer to outside temps.
I would put some fuel system cleaner in your tank and see if that helps...