Chosen Solution
I have a refurbished 2019 13” MacBook Air. It’s worked great until yesterday I went to turn it on. It took forever. So I went and cleaned it out, updated and all that good stuff and then it started working perfect again. But then whenever I would unplug it from the charger it would immediately shut off. Now it takes forever to turn back on if it does (still works great when it does finally turn on) last night I got it to chime with the Apple logo on screen twice but didn’t fully turn on and hadn’t turned on at all since. Battery says it’s normal and fully charged. Side note: I had it plugged in the charger for ab 3 consecutive months. Any idea would could be the problem? I’ve tried resetting it. Different keys I saw online to restart it. But nothing has worked.
This still sounds like it could still be a battery issue to me. The it powers down as soon as I disconnect the charger and then “it takes ages to boot up” is not unusual for that. Does your fan also seem to run really heavily all the time? I might install coconut battery and see what that says about that state of your battery. You can add screen caps to your original post of the results. It’s possible that the leaving it plugged for a long time is related, but I don’t think you’re alone in doing that and modern versions of macOS are generally pretty smart about charging in ways that maintain battery health.
