This means that it’s not happy, right?

[IronWing]

 

[Muadib]

What the heck is this?

 

[bba-tcg]

Wow.

 

[VirtualLarry]

lead-acid parmigiana?

 

[mindless1]

Battery is not even that old. I'd guess the voltage regulator in the alternator (or some other charging smarts/circuit) failed, or a shorted cell in the battery.

 

[Heartbreaker]

lead-acid parmigiana?

I was thinking someone dropped a pizza on it. I've never seen a battery do that before, even on the internet.

 

[Ken g6]

I had a battery go like this, except its output was blue-green. Maybe just different dyes?

 

[mindless1]

^ The acid ate copper/brass/etc instead of steel.