I tried to start my car today but after a few splutters, the ignition quit (i.e. turning it does nothing now). The inside lights / brake lights don't go on anymore, so I assume the battery's dead. But when I opened the hood, I saw this:
Normally my roommate maintains this vehicle, but he's out of town. He's a pretty knowledgeable mechanic by hobby, so I wouldn't be surprised if he saw this and just ignored it, if he saw no serious issues with it. But, maybe it's a really old cord and just now finally severed.
Is it safe to jump this battery?