Battery Charging limit

[Rei]

i have set the limit to 90% in bios. then, i discovered something interesting. maybe just different from what i saw before.

1. i was expecting the battery level to show as 100%, just the charge limit being done in the background, but no it shows as 90% (limit), always.
2. there is a charge/ discharge going on constantly while plugging in and battery level is at 90% (limit), like it will flucturate between say 87 to 90. I thought it will always be 90% and that the battery will never be used while plugged in.

Appreciate if anyone has any insight to share, cheers!

[MJ1]

@Rei

i was expecting the battery level to show as 100%, just the charge limit being done in the background, but no it shows as 90% (limit), always.

Personally, I wouldn’t want it to show 100% when limited to a lower level. I’ve used Thinkpads which also have a battery limit, and it shows the real battery level, e.g. 80%. On Thinkpads you can control it via an app rather than the BIOS. I hope Framework eventually enables similar control from within the OS.

[akta]

There’s ectool that control the embedded controller, you can set a charge limit with it, works for me:

Exploring the Embedded Controller

I’ve pushed an update to fw-ectool that adds a convenience command for setting the charge limit. I’ve also learned that the charge limit and key mapping can be queried! Charge Limit # Query $ ectool --interface=fwk fwchargelimit 80 # Set $ ectool --interface=fwk fwchargelimit 65 65 Key Mapping Question: What scancode is emitted by key matrix position r4, c8? ectool --interface=fwk raw 0x3E0C d1,d0,b4,b8,w0 3e0c(...12 bytes...) 01 00 00 00 00 00 00 00 04 08 00 00 |............ …

Edit: This works on Linux ( I assumed you’re using linux on thinkpads, since they are common amongst linux users)

[Edward_Gray]

Impression only, based on my 11th Gen Intel, batch 1.

I have the charging limit set at 85%, the screen display will sometimes show 86%, not charging.

If I am doing something with high electricity usage, even plugged in, the battery charge level can go down.

Example: running MS Flight Simulator, connected to a Samsung 45w charger, after a long 90? minute flight, the charge me message started to appear.

Flight Simulator is CPU and GPU intensive, so the fan was running full time.

This tells me that the system dynamically adjusts its power draw, charger, if possible, battery to cover higher draw, if needed.

[akta]

FYI I’ve seen someone report that even without setting a charge limit, if the power draw goes up enough (i.e. heavy load), it can discharge while plugged in, if the charger is a 60W charger and that wouldn’t happen with a 100W charger

[Rei]

FYI I’ve seen someone report that even without setting a charge limit, if the power draw goes up enough (i.e. heavy load), it can discharge while plugged in

Upgrading the Framework 13 💻: Is AMD Worth the Hype?

timestamp 16:14

I recall he mentioned about that