The “battery app” say “Battery” (not “Battery 2”) is at 4% battery health and needs to be replaced. Does anyone know which battery that is? I assume there’s one in the keyboard and one in the “tablet” part, but I’m not sure. I don’t want to replace the wrong one then have to open it up again.
I would only trust the BIOS for Battery Health.
Too many various hardware formats to have an app know all battery health formats.
Bios shows “Primary Battery”, health is excellent, and “Battery Slice”, health is poor. After charging for over a hour, the second one shows %0 charge. At least they have names, might help me find out where the bad one is located.
I searched “Dell Venue 11 Pro 7140 battery slice”, and got one hit, apparently the “battery slice” is in the keyboard.
Hi
I have a 7130 Pro Battery is the internal one, Battery 2 is the keyboard, easiest way is to undock 
If you run upower -d (or dmidecode) it will show all the battery information… But if you get into the BIOS (power on (vibrates) press and hold volume up key it has detailed information as well.
I installed Florence to have a virtual keyboard, then disconnected from the keyboard, and started it up. The battery applet shows just “Battery”, and battery health is 81%. So the bad battery is in the keyboard. Now I know which battery to replace.
Now to build up my available credit 