Here's a quick and easy fix for the turning off at 40% battery issue that people are seeing after running Linux. This is effectively the same fix as unplugging the battery, but does so without having to take apart the Switch.

Step 1: Download attached fusee-linux-battery-fix.rar
Step 2: Extract and load the binary with your favorite RCM Smash tool (I'm using TegraRcmSmash).
Step 3: You should see the typical fusee screen, at this point unplug the USB cable. The screen should go off.
Step 4 (optional?): Hold the power button for 10 seconds. Your switch won't turn on at this point, that's desired.
Step 5: Plug in a USB cable. Switch will turn on, and you're done.

This worked to fix my Switch, let me know if it works for you.

Edit:

Source is here:

github/crystalseedgba/BatteryFix/blob/master/fusee/src/main.c (Sorry it's not letting me post hyperlinks)

This doesn't fix the Linux bug, this is really just a crude workaround. At first I suspected that Linux is somehow mangling the battery gauge but this doesn't seem to be the case. The battery gauge reports around 40% and decent battery voltage when my Switch would turn off. I think Linux is misconfiguring some undervoltage lockout somewhere, but I don't know where.

Thanks to jjbredesen for his "How to make a custom Fusee payloads" tutorial.

 

[leonmagnus99]

Big thanks OP, gonna actually charge my Switch after months then run this!

must it be fully charged before sending this payload?
can i use the tx menu to send a payload?

im hopeful for this to fix the slow charging thing as well. (had no power off on lower %)

 

[SomeGamer]

must it be fully charged before sending this payload?

I assume not, but I'm going to fully charge it before sending.

 

[Notex]

must it be fully charged before sending this payload?
can i use the tx menu to send a payload?

im hopeful for this to fix the slow charging thing as well. (had no power off on lower %)

No I did mine at 97% charge and it's worked fine. And I assume it'll work with the TX menu.

 

[xXxSwagnemitexXx]

i did mine at 99%

 

[leonmagnus99]

No I did mine at 97% charge and it's worked fine. And I assume it'll work with the TX menu.

cool, its no biggie.
i could just power it off, i have autorcm enabled.

and in the autorcm mode i only need to send payload.
but then what exactly would happen?

will something pop up ? some ui ?
if not , then can i proceed to sending the tx payload to boot into cfw.

 

[natinusala]

Where does this come from ? Could we have the source code ? I'm not running this without a source code.

 

[xXxSwagnemitexXx]

and in the autorcm mode i only need to send payload.
but then what exactly would happen?

it tells you to unplug the USB cable

 

[SomeGamer]

cool, its no biggie.
i could just power it off, i have autorcm enabled.

and in the autorcm mode i only need to send payload.
but then what exactly would happen?

will something pop up ? some ui ?
if not , then can i proceed to sending the tx payload to boot into cfw.

I'd definitely disable autoRCM before running this. Not an expert on the matter but autoRCM is known to do some weird things to the battery/charging.

 

[leonmagnus99]

it tells you to unplug the USB cable

gotcha, so when im sending payload it will tell to unplug and thats it?
will it reboot into ofw or something after ?

I'd definitely disable autoRCM before running this. Not an expert on the matter but autoRCM is known to do some weird things to the battery/charging.

darn it, im too lazy to keep sticking foil in it.
is it rly a bad idea running this payload from autorcm? ._.

 

[xXxSwagnemitexXx]

gotcha, so when im sending payload it will tell to unplug and thats it?
will it reboot into ofw or something after ?

once you unplug the USB the screen goes black, you hold the power button for 10 - 15 seconds (nothing will happen, which is good). You then plug the USB back in and it should boot to OFW

I did this without AutoRCM tho, so if you have that then it may be different

 

[leonmagnus99]

once you unplug the USB the screen goes black, you hold the power button for 10 - 15 seconds (nothing will happen, which is good). You then plug the USB back in and it should boot to OFW

I did this without AutoRCM tho, so if you have that then it may be different

better to be safe, so jamming foil in again it is then..
hmm, i'll see how it goes.

as long as this solves battery issues then cool, but what about having autorcm enabled again after doing this ? :l
is autorcm the reason for these battery issues or tx os cfw ?

if its tx cfw, then is there a chance of the bug returning after booting back into tx cfw x.x?

 

[xXxSwagnemitexXx]

better to be safe, so jamming foil in again it is then..
hmm, i'll see how it goes.

as long as this solves battery issues then cool, but what about having autorcm enabled again after doing this ? :l
is autorcm the reason for these battery issues or tx os cfw ?

if its tx cfw, then is there a chance of the bug returning after booting back into tx cfw x.x?

the bug is caused by running linux/shofel2 or from a bug in firmware 3.0.0 (i think its 3.0.0, i dont remember exactly though)

 

[leonmagnus99]

the bug is caused by running linux/shofel2 or from a bug in firmware 3.0.0 (i think its 3.0.0, i dont remember exactly though)

yep percentage bug was in 3.0, but i updated some days ago to the latest after i got my tx os license ._.

 

[xXxSwagnemitexXx]

yep percentage bug was in 3.0, but i updated some days ago to the latest after i got my tx os license ._.

cool

 

[NeoSlyde]

Okay i did it
i'll run Mario Odyssey and see where it's gonna turn off (49% before)

 

[Bartesco]

Playing Zelda at 34% and it doesn't turns off, this seems to work. THANK YOU!!!

Enviado desde mi SM-G930F mediante Tapatalk

 

[Dmafra]

But if you use linux again the bug return?
Can it be integrated with lakka?

 

[BlastedGuy9905]

Here's a quick and easy fix for the turning off at 40% battery issue that people are seeing after running Linux. This is effectively the same fix as unplugging the battery, but does so without having to take apart the Switch.

Step 1: Download attached fusee-linux-battery-fix.rar
Step 2: Extract and load the binary with your favorite RCM Smash tool (I'm using TegraRcmSmash).
Step 3: You should see the typical fusee screen, at this point unplug the USB cable. The screen should go off.
Step 4 (optional?): Hold the power button for 10 seconds. Your switch won't turn on at this point, that's desired.
Step 5: Plug in a USB cable. Switch will turn on, and you're done.

This worked to fix my Switch, let me know if it works for you.

I did this. Now, I'm going to use my Switch in handheld mode for a good few hours. If this works... I will be left speechless.

 

[Notex]

But if you use linux again the bug return?

Yes.

 

[NeoSlyde]

It’s surprising that a newcomer with one post made a fix that no one could do it before :o