Ignore what is/is not appearing on the screen - just type in your password, followed by Enter, regardless of what the cursor does and regardless of what does/does not appear on the screen.
AlBags - I'm not familiar this particular model, but am pretty sure that, like other Acer stuff, the CMOS battery is encapsulated in a green plastic overcoat, soldered to the mobo, and access to it requires removing the keyboard from behind (inside the main battery compartment) - hence my previous post of "not a DIY job"