Battery Capacity MacBookPro M3pro

All rechargeable battery slowly lose capacity. The figure used to calculate "health" is inexact because it is the average expected capacity of the battery design, not the actual capacity of one battery. It is the "nature of the beast" within the manufacturing process for individual capacities to vary. All manufactured items have allowable tolerances from a design target.

Health is also non-linear. My Macbook Pro's battery health plummeted almost 10 percent over a few weeks and then recovered to its previous levels. The battery in my 11-year old Macbook Pro is the orignal and and is still just over 80% health. Only now is the runtime becoming shorter.

As far as I can tell, "health" only exists as a threshold value for Apple techs to determine if a failing battery will be replaced under warranty. For years Apple have said that if a battery falls under 80% health at less that 1000 cycles in a computer still in warranty coverage, the battery may be replaced under warranty. I see no other use for "health."

Please do not obsess over an inexact and non-linear metric. Apple uses very good internal batery management to maximize perforamnce, runtime, and battery life.

You pretty much have it correct. I have been extremely busy this week so I am only providing what I recall, but I believe you want to use the "AppleRawMaxCapacity" value in the computations since that is the Full Charge Capacity (FCC) of the battery. I'm not sure what the "Nominal" value indicates as I haven't had enough time to watch it or explore it. I am still in the process of writing a script to mimic the output of the "pmset -g rawbatt" output (at least the relevant portions), but I haven't had the time or need to finish is yet although with some of our M1s approaching that age where I may need it.

The "MaxCapacity" shown by the OP is the same incorrect broken value listed from the "pmset" command....for the Intel Macs it used to be the actual FCC value.

@chdsl is correct that the battery's FCC (aka real "Maximum Capacity" value shown in Apple System Profiler & Battery System Settings) does fluctuate a lot when displayed as a percentage value. Here is another post where I give an example:

Battery Health draining fast -- hwtech - Apple Community

I haven't monitored the M-series batteries enough yet, but it seems the Max Capacity may drop by 5% then level off. This drop could happen within a month of purchase, or perhaps after a year of use. I have an M1 & M2 laptop which has been running Coconut Battery so I have a little bit of history (polled only at certain intervals so not all that accurate). But the Max Capacity value will show fluctuations to varying degrees (both up & down) for all its life with those fluctuations getting more severe as the battery ages. The more severe fluctuations especially recorded over a very short period of time (about 30 minutes during a stress test) indicates a worn out or failing battery.

The best advice I can give to people is to just ignore the battery health information & just use the laptop until the battery no longer performs to expectations, then & only then look at the battery health information to see if it confirms your suspicions of a battery issue. Unfortunately unless the user monitors the battery's values minute by minute under extreme load or fast charging, many battery issues may not be able to be confirmed with any useful data. Even Apple's "Service Recommended" condition seems to only be triggering once the FCC (aka Max Capacity) is less than 77% of the original Design Capacity (this only started occurring recently....both Intel & M-Series Macs). Users can also try running the Apple Diagnostics to see if any hardware issues are detected, unfortunately the diagnostics rarely report issues even when a known hardware issue exists confirmed by other means.

Disclosure: It has been a little while since I worked on my script to monitor these battery values, but I believe I have the key values correct & information correct.

My Intel MBP shows FCC as amount, at this given moment. Maybe in M chip that command doesn't work as it should be. But the 2nd command,

ioreg -l -r -n AppleSmartBattery 

of course, while showing a lot of info, it shows the max capacity and design capacity.

"MaxCapacity"/"DesignCapacity" would give the battery health % at the given moment.

The thing is, this battery health changes from time to time, should not worry th owner much, until if it goes rapidly down and below 80%.

For example, today it shows 86.9%, yesterday, it showed 91%, a few days ago, 92.3%. And, tomorrow it might show 91-92% again. This is a 5 year old battery, and it's doing well.

"AppleRawMaxCapacity"/"DesignCapacity"= 5689/6249 = 0.91, so your battery health is 91%. But, remember it changes from time to time. Try again in the evening, it might be different. If you charge the MBP to full, and then keep it always connected in "optimised battery charging mode", and. after a while it battery charge goes down to 80% and stays there, try again.

But, your usage method, 90% in the office (connected) and 10% underway (w/o charging) might not work with optimised battery charging mode. But, if you connect the MBP at home, immediately after coming home, that mode might catch up.

I have an Intel MBP, so the working of the devices might be different. I have the option optimised battery charging mode enabled always, connected to electricity or not. Sometimes I shut down the MBP when the battery level at 80% in that mode, let it rest for the night (~10 hours), then plug in again in the morning. The optimised battery charging mode catches up and battery level stays at 80%.

By the way, now the battery health has gone up to 87.1% since my last psot.

My battery is 1917 days old (or young) 😊👌

Manufacturers for Apple make good batteries, I think you shouldn't worry so much, and enjoy your Silicon MBP!

chdsl wrote:

In Terminal, do

pmset  -g  rawbatt

It says your battery is very good. FCC=100. Full-charge capacity (FCC) is the total amount of energy you could extract from the fully charged state until empty.

FYI, some of the information output from this command is not accurate on an M-Series Mac. The "FCC=100" value never changes. My 2020 M1 laptop still shows the "FCC=100" value, but that is not correct when compared to the information in your other "ioreg" command you provided and what Coconut Battery reports.

The output of that command is perfectly fine for the Intel Macs. For some reason Apple decides to make things work differently....even breaking it.

Also, you can get all kinds of information, if you do in Terminal

ioreg -l -r -n AppleSmartBattery

The output of this command does contain the proper information if you can find it since it includes a lot of crazy stuff in the output many times with the same "keys" being listed multiple times, but with different values. From my own attempt at utilizing the output, the only values worthwhile are the ones with the "=" sign....usually printing on their own single lines. The output order can vary between usage.

Another option is to use the third party app Coconut Battery which provides the information in an easy to use & read GUI interface.

On 2nd thoughts,

"AppleRawMaxCapacity"/"NominalChargeCapacity" = 5689/5841 = 0.97, that is 97%. The coconutbattery app will give you the real results.

Maybe @HWTech could give a better explanation as he has a M chip MacBook.

The manufacturers for Apple make good batteries, I think you shouldn't worry so much, and enjoy your Silicon MBP!

Yes. That's actually quite good. Were you expecting more?

Yours is not a reasonable expectation. When a battery is new, its maximum capacity is 100%. Once a battery is placed into service, it is no longer new.

In Terminal, do

pmset  -g  rawbatt

It says your battery is very good. FCC=100. Full-charge capacity (FCC) is the total amount of energy you could extract from the fully charged state until empty.

Also, you can get all kinds of information, if you do in Terminal

ioreg -l -r -n AppleSmartBattery