Information about Charging LED (full threshold)

[maniacx]

Hello @c---

I developed a Gnome extension called Battery Health Charging a while ago for several laptop brands/models which also included Apple Intel laptops using your kernel module applesmc-next.

However lately I revisited your page and noticed a note:

Note that for charge_control_full_threshold to work it needs to be set to a value less than than the end threshold because the battery will tend to float slightly under the maximum. Subtract at least 2% or more from the end threshold

I may have missed the LED info earlier, but I am assuming that it probably ligths green when battery level has reached to a threshold value.

1. I would like to know what is the reason to have LED status user configurable?
   Why haven't you hardcode automatically set LED status to charge_control_end_threshold - 2 instead of giving users option to manually set it?

2. Is there a reason that users may not want to set it to charge_control_end_threshold - 2 ?

I don't have a mac, so I just want to get clear information of what LED does and how the charge_control_full_threshold works and why is it needed.

I did add the function to my extension to set the LED sysfs path value charge_control_full_threshold to charge_control_end_threshold - 2 using this commit
maniacx/Battery-Health-Charging@f844c38

But then, I thought of getting a second opinion from you, if I should include or revert this.

[c---]

Yes, that option makes the LED on the charge plug turn green when it's "fully charged". The option for the user to change that is just because the SMC allows it.

I don't know if most people want it to turn green when it's not really fully charged. For example I don't change the full threshold because by never turning green it reminds me the laptop is only partially charged in case I need to switch to full charge mode before taking it off the charger. However, a lot of other brand laptops do show a full charge even when they're not really.

I can't say for sure which is better, that's just how I use it. This is why I left it up to the user preference.

[maniacx]

Last question.

If the user doesn't never changed the value of charge_control_full_threshold , by default what is the value of charge_control_full_threshold?
100 or 98?

Also if user has changed charge_control_full_threshold to 60 and decides, they want change it back to original behavior, what should they set it to? 100 or 98?

[c---]

95% is the default on my 2015 Air after resetting the SMC.

[maniacx]

Thank you for all the information.
I have included an option in extension preferences to enable / disable charging leds behavior.

On enabling this setting

if charge_control_end_threshold >= 97 then charge_control_full_threshold = 95

if charge_control_end_threshold < 97 then charge_control_full_threshold = charge_control_end_threshold - 2

On disabling this setting
charge_control_full_threshold = 95 command will be set once (to restore default behavior) and not be used again

Thank you Chris