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I just recently bought a Macboook Pro Max M2 with 64GB, 12 CPU cores, 38 GPU cores. The previous owner advertised the battery cycles count to be 36, which kinda shocked me and I bought it right away while being sure it really does have 36 cycles. The warranty is until end of January so it is about 11 months old. He said he had it plugged in most of the time and that he used it quite frequently as he's a software dev.

I hoped to keep the low number for quite some time and even thought I had some plugged-off sessions, most of the time it was on the charge.

It surprised me that it has 49 cycles now since 22. 12. 2023, which is ~14 days. That's ~1.13 cycles/day. I checked ac -p and it says my user has run the Mac for 330 hours. That's 23.57h/day. I understand that it's simply saying I didn't log off my user even thought it was asleep. Fair enough. But then I ran sudo smartctl --all /dev/disk0 and got

Data Units Read:                    22 660 414 [11,6 TB]
Data Units Written:                 37 447 305 [19,1 TB]
Host Read Commands:                 710 099 037
Host Write Commands:                1 043 230 198
Controller Busy Time:               0
Power Cycles:                       149
Power On Hours:                     612
Unsafe Shutdowns:                   7

612 power on hours means ~12.5hours/cycle, which seems like the plugged in Mac does not cycle as fast as it does without. Or is the power on hours counting even when the Mac is kinda sleeping in my backpack taking less energy? How do I really check how long has been the Mac used and is there anything I am maybe doing wrong that makes the battery cycle faster?

Martin.
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  • A charge cycle happens when you use all of the battery's power—but that doesn't necessarily mean in a single charge. For example, you could use half of your laptop's charge in one day, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two. – Ruskes Jan 05 '24 at 18:44
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    The disk power cycles count is how many times the disk has been powered up (and later down) - not battery cycles. Disk power on hours is the time that the disk has been active - does not include time when the power was on, but the SSD not doing anything. (my always on, nearly 5 year old iMac shows boot disk as having ~7000 power on hours (~300 days)). – Gilby Jan 05 '24 at 21:53
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    Only 36 battery cycles in 11 months is not necessarily good. May indicate that the battery has spent a lot of time powered on at or near 100%. Get Coconut Battery to get a better idea of the battery's condition - that is full charge now compared with design full charge. – Gilby Jan 05 '24 at 21:59
  • @Gilby Well I would keep it at 80% all the time, but Apple doesn't have such option sadly – Martin. Jan 05 '24 at 22:40
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    AlDente is the popular app to keep battery at 80% (or whatever you choose) https://apphousekitchen.com It is mentioned in many answer to AskDifferent. I use the Pro (paid) version. – Gilby Jan 06 '24 at 02:28
  • https://apple.stackexchange.com/questions/406957/can-i-tell-my-mac-to-charge-to-80-only has answers to keeping battery at about 80%. When I got my M3 MBP I tried Energiza Pro and AlDente - decided that AlDente with Pro option was best. – Gilby Jan 06 '24 at 03:56
  • @Martin The "Optimize Battery Use" setting will keep the battery at 80% when it's left plugged in for days. Generally, I shouldn't worry. I've seen some people micro-manage their battery and have it useless in a few years; and other people leave it on 100% for 5 years and still have decent life left. – benwiggy Jan 07 '24 at 11:59
  • @Gilby please add it as an answer, so I can accept it. Using AIDente ever since and fell in love with it – Martin. Jan 20 '24 at 23:05

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