so I have a 2019 MacBook Pro 16" on Catalina 10.15.5. I recently got it back from the shop - upper case replacement for bad keyboard that included replacing the battery as part of the repair. Now I've noticed that while its plugged in and 100% charge and I'm using it, the battery charge actually decreases. For instance last night I opened it, it was plugged in at 100%. I used it to make an email and print a few pages for 15 minutes and the charge actually decreased to 93%. The icon shows when plugged in.

I have looked at MacBook Pro battery drains when connected to AC power but Battery Health Management is not turned on so it seems to be something else in my case.

How can I diagnose and solve this issue?

PS: I'm using an OEM 96W power adapter.

  • Could it be Catalina’s Battery Health management doing what it’s supposed to do? Apparently they’ve introduced new software to allow your battery to drain a bit (even when plugged into AC) and then charge up again to improve the battery capacity. Having it fully charged all the time deteriorates the long term health of the battery, hence the new Battery management software introduced in Catalina – AVelj Jul 16 at 3:58
  • The way Apple cs explained it to me is that BHM is suppose to only charge to a less than 100% state - not go to 100% then run down while plugged in... Unless I missed it, nowhere in the bulliten does it say it’s suppose to run down while plugged in. support.apple.com/en-us/HT211094 – Stumped Jul 16 at 14:01
  • I'm a bit confused here: In the question you say that BHM is not activated, so why is the support article relevant? Also, as you use an OEM adapter, can you use the Apple one for a day or two to see whether it makes a difference? – nohillside Jul 16 at 14:41
  • BHM is the feature introduced in Catalina where you can interact with the feature (i.e. enable/disable). That doesn’t preclude Apple from implementing the charging management in earlier versions of macOS. See this answer for more details. Everything you are seeing is perfectly normal. – Allan Jul 16 at 17:59
  • good question no hillside. Allen referenced it in the question he referred me to (or my original question - can't remember which as this bouncing back and forth between is confusing to me) that he said was similar to mine. he bought it up originally not me. OEM(Original Equipment Manufacturer) is Apple. – Stumped Jul 16 at 18:51

Browse other questions tagged .