Alternator problems at idle on L78 Camaro

[Jeff H]

It looks to be a new battery but rather weak(555 CCA) so I topped it off on the charger for 16 hours and the lights are definitely brighter at idle now. Rev it a little and they get a little brighter but not a lot. It's reading 13.8-14 volts at idle with no lights on and drops to 13.6-13.-8 with the lights on. Then it will jump up to almost 15 volts when you rev it a little. So I don't think the alternator is a problem. I will want to get a correct 837 alternator eventually but this one should work for now. It needs a stronger battery IMO.