I ride my C500 almost daily. The yellow battery barely lasted 2 years.
I found that they didn't fit well, nor does the new replacement but I noticed what's really stopping it is the battery compartment lock barely makes it to the spot where the barrel rolls closed. So I just pushed it a bit harder and it made it through. My 2010 C5 seems to be one of the models that had a lock on every compartment, battery box, tool box (no tools in it, of course), airbox, electronics box, etc etc etc.