exclamation point in triangle on ipod classic

I have plugged in my dad’s old probably generation first iPhone into my iMac to charge and download his music. He hasn’t used it for probably 10 years. Because he has passed away. I am getting a icon of a battery with an ! Inside a triangle on the left side of the battery picture. And, the iPhone does not show up in iTunes. So does this mean I need to get a new battery? It goes back-and-forth from that to the Apple logo.