Puzzling Battery Threshold Behavior

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1

I enabled the battery charge threshold using framework_tools and set it to 80%.

Based on the ec source code I found on github, it looks like it’s supposed to do this:

0 ---------- 75 ------- 80 --------100
    Normal       IDLE      discharge

It does work normally below 75%. It does discharge the battery if it’s more than the threshold of 80%. But when it gets to 80% it doesn’t IDLE, it’s still pulling power from the battery. In IDLE mode I lose 1% of the battery per hour, so you’d assume it’ll take 5 hours to go from 80% to 75%, but it takes less than an hour, so it’s constantly charging and discharging the battery.

I also tested using the BIOS, and set the threshold to 60%, and saw the exact same issue.

This doesn’t make any sense to me, does anybody else see the same issue? It’s pulling a constant 5W-7W from the battery (the system is using more, so it drains slower than if it were not connected to the AC, but you’d assume in IDLE mode, it pull ~0W from the battery).

[The image is my current test with threshold at 60% via BIOS, you see it drained faster when it was above the threshold, and slowed down when it got to 60, but it’s charging and recharging that 5% every hour]

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Here’s another image showing battery draining at 6W:

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It looks like that only at 60% and at 56% it was actually IDLE:

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I turned off Battery Extender in the BIOS. Didn’t change anything.

system info:
Vendor: INSYDE Corp.
Version: 03.20
Release Date: 06/23/2026
Address: 0xE0000
product: AMD Ryzen 7 7840U w/ Radeon 780M Graphics
vendor: Advanced Micro Devices [AMD]
physical id: 4
bus info: cpu@0
version: 25.116.1
I’m on PopOS 24.04

2

I know this reply is gonna seem a little far-fetched since I’m on a completely different system (i5 Framework 12) but in my experience, using a very high wattage charger (like 100W) will ensure that 0 watts are actually drawn from the battery at all times regardless of system load. If I use a lower wattage charger like a 45 watt one, which, according to the math, should sustain the entire system at max load, sometimes I catch the battery being drawn from by like 0.5W or so while the system is in heavy load with the 45W charger connected.

I might be spewing nonsense here, but you may want to try using a higher wattage charger before doing anything else.

3

I have a 100W power supply connected, and my system is pulling a lot less (20W max).
The draw from the battery is a constant 5W or 6W, regardless of the load.
Looking at the ec console log, it reports the battery “parked” only when the percentage is 60%, as soon as it gets below 60%, it starts drawing (not “parked” anymore, while reporting “not charging”) a constant amount until it gets to 55%.

4

This is definitely a bug. If you used a 45W or 60W charger and play video games it’ll slowly discharge at about 0.5W until it reaches 5% lower. It’s discharge above 80%, charge below 75% and idle at between 75 to 80%. If you start at 80% and a sharp pulse load drags the battery to 79% it should continue idling at 79%.

In OP’s computer, it can only idle at 80% a sharp pulse load drags the battery to 79%, instead of idling, it changes to discharge and discharges to 75% before changing to normal again. That’s why OP shows 7W drain, identical to idle drain on pure battery, instead of 0.5-ish W drain

5

I think I found the issue.

It looks like when it sets the mode to IDLE it sets current and voltage to 0. Then overwrites the voltage by 1 voltage step, which is not high enough, so as soon as there is a little load, the diode conducts and starts leaking. and since the current is 0 it never gets biased again, until we reach the min we switch to Normal mode, and we’re good.

Setting the min and max both to 60% fixes this issue (you can do it using the kernel driver). The reason that works is because as soon as it goes below 60% the voltage is set to max, so the diode is fine. and IDLE doesn’t leak.

I have confirmed setting 60% as both min and max fixes the issue. And currently am compiling the ec, to flash it with a fix for the scenario where min < max.

Opened a PR:

6

What happens if a 60W charger is used? Does it going to drag the voltage from max all the way to battery voltage so the battery can supply power during peak loads?

7

Yeah, works fine. Here I charged to 60% using my SteamDeck charger which is rated 45W. It parked the battery when it got to 60%, I ran a couple of compiles, it pulled from the battery when compiling and parked when finished:

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