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.

 

[TR_mahmutpek]

It worked flawless for me even I never used linux before. Thx OP!

 

[TR_mahmutpek]

@Crystallseed Can you make this app for joy-cons also? Or is there a app like this exist?

 

[Brando72]

is this still confirmed to work? is there a more modern method?

 

[SomeGamer]

is this still confirmed to work? is there a more modern method?

I think Hekate now does this at every boot.

 

[TR_mahmutpek]

İ

is this still confirmed to work? is there a more modern method?

Its just a paylod bro, just send via tegra rcm and done, ita fixed its easy. This payload dont need any update i think. So its enoug modern.

 

[ritchiedonovan]

Noob needing help from the resident geniuses at gbatemp!

So I use sxos and and hadn't used my switch for a few months. I turned it on today and the battery was all over the place - said it was at 79% when it was practically at 0%. I charged it for 3 hours (it was on 100%) for a couple of hours and then removed the charging cable. It is taking a long time for the battery to go down - it's at 92% and I've had it on for over an hour. So I think this battery fix might be what I'm looking for? Is there an easy way to do it via SXOS? As I said I am pretty hopless at these sorts of things so any advice greatly appreciated!

 

[TR_mahmutpek]

Noob needing help from the resident geniuses at gbatemp!

So I use sxos and and hadn't used my switch for a few months. I turned it on today and the battery was all over the place - said it was at 79% when it was practically at 0%. I charged it for 3 hours (it was on 100%) for a couple of hours and then removed the charging cable. It is taking a long time for the battery to go down - it's at 92% and I've had it on for over an hour. So I think this battery fix might be what I'm looking for? Is there an easy way to do it via SXOS? As I said I am pretty hopless at these sorts of things so any advice greatly appreciated!

Just send this payload, it wont break anything and probably fix the issue.

 

[ritchiedonovan]

Thanks for the reply! I use the dongle to enter sxos - is there a way to use this fix with sending the payload without hooking it up to a pc?

 

[TR_mahmutpek]

Thanks for the reply! I use the dongle to enter sxos - is there a way to use this fix with sending the payload without hooking it up to a pc?

I dont know about sx os, never used it but if i remember correctly, payload on dongle should be changeable. Search for that..

 

[gnmmarechal]

I dont know about sx os, never used it but if i remember correctly, payload on dongle should be changeable. Search for that..

I don't think that's the case. The SX Pro is hardcoded to launch the boot.dat. Now, you can use the SX Gear boot.dat and load something else, buut yeah.

 

[ritchiedonovan]

Thanks for the help guys, I managed to fix it (I think) by doing what Nintendo suggested (charging for 4 hours, letting it drain on the home screen etc) and it seems okay now.

 

[whateverg1012]

Is it safe to use this while autorcm is enabled?

 

[TR_mahmutpek]

Is it safe to use this while autorcm is enabled?

Sure.

 

[nero99]

you don't need to use this anymore. hekate has has this coded into it for quite a while now.

 

[TR_mahmutpek]

you don't need to use this anymore. hekate has has this coded into it for quite a while now.

Nope, I fixed my problem with only this payload. Hekate dont work for me.

 

[whateverg1012]

Nope, I fixed my problem with only this payload. Hekate dont work for me.

How exactly did you use this? I injected this payload but my battery is still not fixed (still shuts off at around 40%), do I inject this payload when my battery reports to be at 100% or when it's at 40%?

 

[TR_mahmutpek]

How exactly did you use this? I injected this payload but my battery is still not fixed (still shuts off at around 40%), do I inject this payload when my battery reports to be at 100% or when it's at 40%?

My problem was this; My battery shows wrong percent, still I can play rougly 3 hours but switch battery dies at 50, than 75, than 90 etc. I send this payload and resetted the battery stats and back to normal. What is your switchs problem? Also I think you just need to send payload, no need to charge.

 

[whateverg1012]

My problem was this; My battery shows wrong percent, still I can play rougly 3 hours but switch battery dies at 50, than 75, than 90 etc. I send this payload and resetted the battery stats and back to normal. What is your switchs problem? Also I think you just need to send payload, no need to charge.

I can also play around 3ish hours in handheld but my switch dies somewhere between 40-45% (so my battery is showing the wrong percent)

I sent this payload but it still dies around that point. The payload was sent properly because my clock got reset which indicated that it worked.

I've basically given up at this point though, just gonna accept that 40% is my new 0% now. Hoping it will fix itself over time.

 

[TR_mahmutpek]

I can also play around 3ish hours in handheld but my switch dies somewhere between 40-45% (so my battery is showing the wrong percent)

I sent this payload but it still dies around that point. The payload was sent properly because my clock got reset which indicated that it worked.

I've basically given up at this point though, just gonna accept that 40% is my new 0% now. Hoping it will fix itself over time.

Interesting. It worked for me but on nearly impossible levels. I mean switch battery shows 100 or 99 but its actually 0 or 1 (yes!) and it cant charge itself because it reads battery 100 and rejects electricity i think. I sent this and worked. Showed 0 and charged normally. Maybe you should wait for worse percent or ask op, Ctcaer.

Oh, alternatively, you can dissasembly and eject switch battery manually, which this payload does that but you can try if you want. So maybe maybe will work.

Hope you will fix issue soon.