E7470 (25GGG) Question about two FN-keys and odd battery behavior

I haven't been able to figure out what two of the blue function keys do. I browsed all the documentation, including the unabridged manual, but couldn't find a lexicon of any sort. They are the ones under F5 and F6. Both symbolize closed locks. The other one has a number nine in it and the other one a vertical arrow with dual heads. Neither seems to do anything. I thought the first one was a number lock for the integrated keypad, but appears not to be.

My other question regards a battery behavior I encountered just today with my brand new Latitude. I was doing a light web browsing when my system reached a thirty percent battery level. I was under power saving mode in Windows 10 Pro x64. All of a sudden the system turned off. When I plugged the AC charger in and pushed power button, I resumed into Windows logon screen, which suggest the system went into suspended state. I have set the threshold for that much lower. The reason for my worry is that now that I had resumed back to Windows, the battery appeared to be almost completely drained and showed just 2 percent charge left, as it had just a few minutes earlier showed 30 % and several hours of usage left. What I wanted to ask is that is this normal behavior or a sign of something wrong? Could a brand new laptop battery exhibit this erratic behavior? I have 18 hours of usage on the new laptop and not once before has the battery status took a leaps of any sort to either direction.