I have a late 2016 Macbook Pro with macOS 10.13.2 installed. I've had this problem from at least 3 months.
At first, the battery percentage wasn't dancing like crazy but today it happened. When I check my battery capacity with coconutBattery it is decreasing normally but when I'm looking at macOS battery percentage it wiggles and doesn't decrease normally.
Sometimes, my Mac crashes when I don't have anything open except chrome and discord.