Battery issue?

I drove the blue car to work yesterday. First time ever! Sometimes it's slow to start, like the battery may be weak. Guess I need to check it but I've never seen it. I know it's in the trunk somewhere. The code that it threw at Todd's has cleared and the issue hasn't returned. Never did get Dwight to scan it. 

Next I need to order the new fans for the purple car and get it to Clayton's to hopefully fix the overheating issue. I'd like to have it ready for spring.