Hello, I helped a friend replace his battery terminals today. The battery was not secured at all apparently and the positive terminal of the main battery has what I think is crazy electrical damage to the metal. The 2 small holes are burned out almost to the largest hole in diameter. Am I correct that this is potentially a very serious issue?

 

Electrical discharge machining.... Not something you wanna see on your battery terminals..... Replace the terminal, and make sure the battery is secure.

 

Yes, bad juju. Something was either shorting out or the wire in that small port was loose. Loose wires will cause poor connections resulting in arcing and heat buildup which is what it appears you have there.

 

Thanks, seems incredibly dangerous and negligent by whoever replaced the last battery to not secure the bolt attachment.