Chosen Solution
My MacBook Air which is relatively new has just recently started charging to only 99%. I’ve charged it twice in the meantime and it’s never been 100% after I unplug it, as usual (I believe) and always just 99%. Can someone help me out?
I would attempt an SMC Reset, this can help with Battery management and various other things. To do this reset follow this guide on apple’s website. https://support.apple.com/en-us/HT201295