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My MacBook Pro (2016) Retina is suddenly only charging when it is turned off or in sleep mode. I've tried a bunch of things already and a quick check by the Apple support desk didn't show any problems so I hope someone else had te same issue. I've tried:

  • SMC reset
  • Reset my entire laptop back to factory settings & reinstalled MacOS Big Sur
  • Checked with another charger
  • Battery health is 'good'
  • Turned off optimise battery life

I'm in the middle of finals so hopefully I can find a solution! Thanks :)

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  • Newer Macs can be hard to diagnose; generally this happens when more power is used than the charger can supply, or when the machine thinks that it is the case. Can happen with bad sensors, bad power circuit, bad charger, bad battery, bad cable, bad software. Some of those you already eliminated, others are hard to test by the end-user. Jul 23, 2021 at 17:30

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Has the cable between the laptop and charger been damaged or changed? This sounds like the charger is not seeing a USB-PD cable and so only provides 12 watts of power. If there is a loss of communication for USB-PD negotiation then it might fall back to a simple low power USB-BC mode like iPods would use. 12 watts will charge a laptop while asleep or off but might not keep up with power draw while the laptop is on.

The cable that came with the laptop will most likely be a cable capable of USB 2.0 and 20 volts @ 5 amps of USB-PD power. If you have a different USB-C cable around, or a classmate willing to loan you a cable, then try that. A common USB-C cable for a hard drive or cell phone should be capable of 20 volts @ 3 amps, far better than 12 watts, more than enough to keep up with most computing loads, though not the full 85 or 96 watts of some power supplies.

If you don't have access to a spare then it would not cost too much to buy one from the school book store, a cell phone shop, a big box department or electronic store, or even a grocery store or truck stop. A quality third party 1 meter cable can be about $8, a genuine 2 meter Apple cable about $20. If a new cable solves the problem then you solved the problem. If not then return the borrowed cable, maybe keep the one you bought just in case, and then consider a more expensive problem.

Has the power supply been damaged? Borrow or buy a spare to test that. As I rule I immediately buy a spare charger for my laptops and other important tools. Not an issue lately for laptops since everyone moved to USB-C but still a rule I follow generally. I mention this as a means to avoid a problem like this in the future, having a working laptop but a non-working or questionable charger. It may be a wise investment to keep a spare charger in case of a lost or damaged charger in the future.

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Three likely reasons. You cold have any or all of them happening

  1. You likely have apps / services running in the background, which are consuming significant energy. Only when they are put to sleep/low can the battery build a charge.

  2. If these don't show up in the Activity Monitor under Energy, then the services may be a virus or malware, like a secret crypto miner.

  3. Or your batter is near-dead. Which is just a special case of the above.

I had this happen to me, as #1, with a number of file/data sync services. One would hang bhedin the others, and spin out of control.

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