6hr 33 min to charge last 6% of battery - is this normal? Exactly as asked - I couldn't figure out why exactly this is happening?
No, it is probably not normal.

You can hold the alt key and click on your battery icon.
Then click Condition: X.

What is your X? You can read some more information based on the window that popped up

By the way, does it really take 6.5 hour to charge to 100%? Cause it could just be some temporary mess-up with the estimation.