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mactinkerlover

macrumors regular
Original poster
Sep 20, 2020
173
113
Okay, so I use coconut battery. I noticed a couple of days ago that while my battery had sat at 100 to 102 percent battery health over the last few months. It all the sudden went down to 96 to 97 percent health. Interestingly, system preferences battery health still says I'm at 100 percent health. I use my computer plugged in most of the time, so it did sit at 80 most of the time. However, a couple days ago, I did use it on battery for a while playing a game, so the machine got hot, and after I plugged it in and charged it back up, that's when I noticed the capacity reduced. It just has 22 cycles on it. To my main question now. Is this just the battery health management thing doing its thing? Apparently, you can't turn it off on apple silicon so if that's the case I guess I'm stuck with it.
 

lcubed

macrumors 6502a
Nov 19, 2020
540
326
a quick search on this forum for coconut shows enough results to make me wonder how accurate coconut battery iso_O
 

jdb8167

macrumors 601
Nov 17, 2008
4,859
4,599
a quick search on this forum for coconut shows enough results to make me wonder how accurate coconut battery iso_O
Coconut battery is almost certainly getting it's info from the same source as the macOS ioreg tool. You can get both full charge capacity and current capacity from the command line using macOS itself so it is likely to be accurate.

ioreg -a -r -c AppleSmartBattery |egrep -A1 "DesignCapacity|AppleRawMaxCapacity"

Simply calculate: AppleRawMaxCapacity/DesignCapacity
 
Last edited:

Kazgarth

macrumors 6502
Oct 18, 2020
318
834
It was probably over-estimating your battery capacity at the beginning, mine is also at 97% after 3 months of use according to Coconut, but still at 100% according to MacOS.
 
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jakob95

macrumors newbie
Dec 28, 2016
15
1
I am having the same problem CoconutBattery life is showing 92% capacity left where my cycle count is only at 50. Last week Cocunut showed 94% and when I checked through settings what my battery life was and it showed 99%, but now one week later it is showing 98%. Coconut is already telling me to get my battery checked. Should I be concerned?
 

jdb8167

macrumors 601
Nov 17, 2008
4,859
4,599
I am having the same problem CoconutBattery life is showing 92% capacity left where my cycle count is only at 50. Last week Cocunut showed 94% and when I checked through settings what my battery life was and it showed 99%, but now one week later it is showing 98%. Coconut is already telling me to get my battery checked. Should I be concerned?
Battery degradation is a chemical process and neither Apple nor any other company has Mac control over it. All they can do is statistically sample a large number of batteries under a large range of usage and make reasonable guesses on how long they will last. The batteries in MacBooks are supposed to be good for 1000 cycles. If your battery dies after 600 cycles you probably have a case with Apple to get a replacement.

Having said that, the same chemical process that made your capacity go down by 2% in one week is likely to also likely to have other disproportionate changes. Next time, you might be able to go a month and another 50 cycles and only drop 1%.

Don't discharge your battery to zero. If you can and it is practical, keep the max charge around 80% and the minimum no less than 30%. Exercise the battery by allowing it to discharge from 80% to 50% occasionally. There really isn't much else you can do. Don't stress.

Edit: If the official Apple battery widget or System Preference isn't saying to get the battery checked, I would ignore coconutBattery.
 
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jakob95

macrumors newbie
Dec 28, 2016
15
1
Battery degradation is a chemical process and neither Apple nor any other company has Mac control over it. All they can do is statistically sample a large number of batteries under a large range of usage and make reasonable guesses on how long they will last. The batteries in MacBooks are supposed to be good for 1000 cycles. If you battery dies after 600 cycles you probably have a case with Apple to get a replacement.

Having said that, the same chemical process that made your capacity go down by 2% in one week is likely to also likely to have other disproportionate changes. Next time, you might be able to go a month and another 50 cycles and only drop 1%.

Don't discharge your battery to zero. If you can and it is practical, keep the max charge around 80% and the minimum no less than 30%. Exercise the battery by allowing it to discharge from 80% to 50% occasionally. There really isn't much else you can do. Don't stress.

Edit: If the official Apple battery widget or System Preference isn't saying to get the battery checked, I would ignore coconutBattery.
If I were to go to apple to replace my battery would they be able to do it? My Macbook air 2015 that I had for 5 years with over 800 charge cycles had a 92% battery life capacity until I sold it, this is kind of ridiculous.
 

jdb8167

macrumors 601
Nov 17, 2008
4,859
4,599
If I were to go to apple to replace my battery would they be able to do it? My Macbook air 2015 that I had for 5 years with over 800 charge cycles had a 92% battery life capacity until I sold it, this is kind of ridiculous.
At 90% they aren't going to replace your battery (at least not for free.) You only have a warranty issue if your battery is actually failing. Right now you see a trend you don't like and that isn't going to be enough (in my opinion.)
 

NT1440

macrumors Pentium
May 18, 2008
15,092
22,158
This is not a linear process. A drop in percentage at the beginning of its lifespan is normal, and has always been normal since the inception of Lithium batteries in laptops. It will level off at a certain point and sit there for years.

In short, you’re over analyzing your battery to the point of worrying over normal behavior. Check it every few months at most.
 
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ManicMarc

macrumors 6502
Jul 1, 2012
487
149
It's only an estimate. If you never drain the battery below 20% for example, it will often overestimate the battery capacity (causing some people to believe that draining the battery below 20% is causing some kind of problem - it's not). If you run demanding software that drains the battery quickly, your laptop will start to underestimate total capacity for a while. Battery collaboration is not an exact science. It's a rough guide to assist with informing users when to service their battery or to help diagnose faulty batteries. My 7 year old MacBook Air is on 241 cycles and 86% design capacity. Nowhere near the 1,000 - but it's 7 years old. Which is to say, entropy will get us all in the end, even our laptop batteries :)

Apple charge £129/$129 for a new battery. Instead of worrying about it, put £1 aside each each week for the next 129 weeks, and by the time you reach 1,000 cycles you'll be able to get a new one :)
 
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