I have the same problem as described here:
https://discussions.apple.com/thread/3067544
As no one seems to care about the old post anymore (and there was no solution), I was recommended to make a new post about it...
I tried all the suggested solutions in that older post, nothing has worked so far.
MacBook, macOS 10.14
Please let us know the MacBook model/year. Also did you have any notification earlier about replace battery / service battery.
Have you tried resetting SMC, if not please try and see if that helps.
How to reset the SMC of your Mac - Apple Support
Hope it helps.
New piece of evidence: When I check the System Power Settings in System Information, it only gives me info about AC Power, as if there wasn't any battery at all! But the Mac has been and is running on battery, so this is very weird.
battery status not showing in menu bar, energy saver pane it says battery life is 0%
