Quote Originally Posted by [XC] Lead Head View Post
The blue gunk looks like copper sulfate. Your battery was probably venting some sulfuric acid into the terminal area, reacting with the copper in the cable and causing that corrosion. I wouldn't be surprised if your positive battery cable fails shortly.

Anyways, as far as lead-acid car batteries go, 12.6 volts is fully charged, and anything less then about 12-12.1 is not going to start your car
Well I believe this was the original battery I'm the 2nd owner and when I bought it had around 20k miles on it 2 years ago. That red cable where the blue is was definitely missing some of the red cable. melted or whatever I guess. However, the cable itself the copper I guess look completely fine none of the copper fibers or strands whatever were sticking out so we taped it up.