Fun fact: I work with both electrical systems and lithium batteries as part of my IT job. Yeah, it's a weird combo, I know. And I'm certified in neither.
Also, I've blown up a lithium battery on purpose at work as part of a battery safetydemonstration.
I was surprised to stumble across a BIOS battery yesterday when I was taking out the drives to copy out some data, so I guess that aspect of it all is OK.