Wrong battery value on MacOS

[b1nhack]

The macchina battery percentage value doesn't match the MacOS system's (about 3 less)

[grtcdr]

It would help if you provided your macOS, macchina and libmacchina versions.

[b1nhack]

MacOS Sonoma 14.2.1
macchina 6.1.8
libmacchina 6.3.5

[grtcdr]

Can anyone with Apple hardware confirm this? If so, please let us know by contributing to the conversation.

[mikemadden42]

I see this issue with the battery too. Let me know if I can help debug the issue.

# native macOS tool
$ pmset -g batt
Now drawing from 'Battery Power'
 -InternalBattery-0 (id=33816675)	93%; discharging; 16:46 remaining present: true

# macchina
Battery     -  88% & Discharging

[grtcdr]

Third-party battery replacements have caused issues, though way more sinister than this, in the past ¹. Are these miscalculations occuring on machines with an authentic battery?

Footnotes

1. https://github.com/Macchina-CLI/macchina/issues/73 ↩

[b1nhack]

Yes! My machine is brand new, from the Apple store.

[mikemadden42]

My MacBook also has the factory installed battery. Utils like pmset -g batt seem accurate while the calculation with macchina seem off.

[grtcdr]

I'll defer this to @123marvin123 as he knows more about the macOS side of things than I do.

[123marvin123]

I'm not sure what could be the reason for these larger differences between the "pmset -g batt" command and macchinas readout. For macchina, the values are coming directly from IOKit. Only minor floating point -> int conversion are expected.

This is what I get on my MacBook Air M1 with original battery:

pmset -g batt
Now drawing from 'Battery Power'
 -InternalBattery-0 (id=22282339)	71%; discharging; 4:17 remaining present: true

Battery     -  70% & Discharging

[platlas]

Not sure what is the difference between the properties of IOPMPowerSource but it seems that CurrentCapacity is the same as one displayed in Menu bar while StateOfChange used in libmacchina 0 represents something slightly different.

At least that seems to be the case when I checked I/O Kit registry, in terminal, on my machine (mbp13 M1):

ioreg -w 0 -irc IOPMPowerSource

I'm including values that seems relevant to me.

While on 100% battery:

  <class IORegistryEntry:IOService:IOPMPowerSource:AppleSmartBattery ...>
  {
    ...
    "CurrentCapacity" = 100
    ...
    "BatteryData" = { 
       ...
       "StateOfCharge"=99
       ...
    }
    ...
  }

And for example on 71%, CurrentCapacity is 71 while StateOfCharge in BatteryData is 68.

(But they can show same value sometimes)