I'm seeing some new behavior recently where my laptop shuts down hard, with no warning, at about 50% battery. After the third time it happened I took a look at the battery levels (after plugging in and restarting) and found that the main battery was at 1% and charging, while the extra battery was at 100% and fully charged.

So it would seem that my system is ignoring the extra battery or somehow not tapping into it at runtime. I don't recall this ever happening in the past and I'm not sure if this is an OS issue or something lower level. 

Anyone seen or know how to diagnose this?

Thanks!

-CB