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djc6

macrumors 6502a
Original poster
Aug 11, 2007
875
467
Cleveland, OH
2019 15" Macbook Pro i9 (2.3Ghz 8 core) with 16GB RAM. Its been plugged into my Caldigit 3 dock the entire time I've owned it, since it just sits on my desk and there was no work travel during the entire time I've owned it. Its sat upon on a Rain Design mStand the entire time off to the side as I use external monitors, keyboard, mouse.

Now we're travelling again for work, and I'm finding the battery lasts 1.5 - 2 hours tops. I'm not sure any applications are burning through my battery - I only use browsers (Chrome & MS Edge), Terminal and Slack.

Coconut battery shows 155 charge cycles (I'm surprised its that high) and 80% of design capacity. 80% of design capacity would be awesome, but I seem to be getting far less than than. Any ideas? Thanks!

1675344941737.png
 

chrfr

macrumors G5
Jul 11, 2009
13,592
7,134
Coconut battery shows 155 charge cycles (I'm surprised its that high) and 80% of design capacity. 80% of design capacity would be awesome, but I seem to be getting far less than than. Any ideas? Thanks!
The only thing you can do is to get it replaced. Laptop batteries that don't get used will wear out due to heat and time, so this is expected behavior.
 
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Fishrrman

macrumors Penryn
Feb 20, 2009
28,759
12,866
Once the "design capacity" of the battery (see Coconut Battery report above) drops BELOW 80% (as in, "79.8%), you should qualify for the $199 battery replacement from Apple.

This is available ONLY through Apple (at Apple Stores) -- NOT from "3rd party providers".

For $199, you get:
- a new Apple-labeled battery
- installation
- a short warranty.

A pretty good deal, really.
I can't swear to this, but sometimes they may replace the entire top case.

But again, the battery's design capacity has to drop below 80% first.
So... take it OFF charge and cycle the battery some.

By the way...
I don't believe it's good for the battery to leave it plugged in and charging all the time.
It should be taken off charge and run down to, say, 45% or so a couple of times a week, then re-connected, to "exercise" the battery.
 

djc6

macrumors 6502a
Original poster
Aug 11, 2007
875
467
Cleveland, OH
I wish the OS could be configured to just use the battery sometimes. If I follow your recommendation and periodically unplug laptop from my Caldigit 3 dock then I also unplug both my 4k monitors, external storage, ethernet, USB headset, keyboard, mouse, speakers, sd card reader, etc, etc... that I'm using all the time

Mostly interested in figuring out how to get the 80% coconut battery claims instead of the 20% I feel like I'm actually getting.
 

iMacDragon

macrumors 68020
Oct 18, 2008
2,390
724
UK
I wish the OS could be configured to just use the battery sometimes. If I follow your recommendation and periodically unplug laptop from my Caldigit 3 dock then I also unplug both my 4k monitors, external storage, ethernet, USB headset, keyboard, mouse, speakers, sd card reader, etc, etc... that I'm using all the time

Mostly interested in figuring out how to get the 80% coconut battery claims instead of the 20% I feel like I'm actually getting.
Is it shutting off suddenly, or doing a big sudden jump in percentage as it gets used? those would be signs of a faulty cell.
 

DeltaMac

macrumors G5
Jul 30, 2003
13,615
4,497
Delaware
80% capacity is generally the point when Apple considers the battery replaceable, and normal, useful battery life may then be unacceptable, and you will sometimes see a quick drop-off of battery performance. If it gets down to 70, or 60%, you might see the battery only last 30 minutes or so from full charge.
 

djc6

macrumors 6502a
Original poster
Aug 11, 2007
875
467
Cleveland, OH
What I don't understand is that this laptop was advertised as having 10 hours of wireless internet browsing, so if my battery was at 80% of rated capacity shouldn't I see 8 hours? not one?

80% of its advertised "battery life" would be awesome.
 

Bigwaff

Contributor
Sep 20, 2013
2,235
1,502
AlDente - Charge Limiter

 

Alpha Centauri

macrumors 65816
Oct 13, 2020
1,280
1,003
What I don't understand is that this laptop was advertised as having 10 hours of wireless internet browsing, so if my battery was at 80% of rated capacity shouldn't I see 8 hours? not one?

80% of its advertised "battery life" would be awesome.
That sounds quite logical actually but unfortunately the degradation doesn't quite work in such a nice linear and predictable fashion. So what they really mean is up to 10hrs at 100%. Anything below that just becomes much less predictable.

Open Activity Monitor (Energy) to see what Apps are especially power hungry.
 

djc6

macrumors 6502a
Original poster
Aug 11, 2007
875
467
Cleveland, OH
Open Activity Monitor (Energy) to see what Apps are especially power hungry.

macOS always reports that Chrome, Slack and Google Drive's FinderHelp.app are using significant amounts of memory. I basically use three apps - Slack, Chrome and Terminal on my work laptop. Some days I might run Spotify, other that that I don't have much installed on my work laptop.
 

AlixSPQR

macrumors 65816
Nov 16, 2020
1,034
5,389
Sweden
The reason that the battery wears down in plugged in computers is that batteries’ chemical composition degrades more when they are charged more than 80 percent. The same applies for less than 20 percent. Ideally, they should be charged between 20 and 80 percent.
 
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