Aren’t there any logs of what Syncthing is actually doing when consuming so much battery? It’s gonna be impossible to tackle without more data. It also seems related to Pixel phones + Android 16? Or are there other devices affected too?
Galaxy S21 FE (Android 15), no issues. Syncthing 2.0.9 (The Google Play release, though, by nel0x).
We already know that the issue isn’t connected to the wrapper but propably lies within syncthing itself. So what phones and Android versions do you actually use, guys? Maybe there is a connection, since we already have three Pixel phones lined up …
Have battery issues
melusine: Pixel 6 Android 16
pdc1: Pixel 6a Android 16
lard0101: Pixel 6 Pro Android 16
No issues
er-pa: Galaxy S21 FE
Hi everyone,
Sorry in advance for my english level 
I’m using Syncthing between 3 devices since 3 months :
Settings & usage :
It works fine but same issue of battery drain since the beginning of my setup.
For example : 52% of battery consumed between 8 am and 12pm today… (80 % to 69 %)
Thanks in advance for your help !
Pixel 8 with stock Android 16 is where I have battery drain.
https://www.reddit.com/r/GooglePixel/comments/1n5knvq/battery_megathread_september_2025/
Just putting it out there, there are many complaints about battery-drainage and battery-protection functionality mot working related to Android 16 or Google Pixel.
But yeah, as said before, more info would be helpful.
If it helps, my phone isn’t a Google Pixel, but a Samsung Galaxy A54
Pixel 7a, Android 16.
OK for now there are six Pixel phones and one Samsung phone reporting battery drain. No drain on Samsung (as well), Xiaomi, Fairphone … So maybe not (?) just Pixel specific?
My linked reddit post was covering a Pixel as well though. 
Thanks, I did not know that. I had also noticed a general degradation regarding battery life on my Pixel but nothing that serious (as seen on your reddit post). All I know is when I stop syncthing-fork or disconnect wifi (which does the same for me), the biggest contributor to battery drain is gone.
Can you please give us instructions on what you need and how to get it? Sadly I am not a developer …
Nobody else in this thread has said they tried this, and there are changes made to NAT traversal in v2:
I’d be interested in seeing the effect of disabling NAT traversal for people with the problem.
Pixel 5, Android 16
I will try that and report back but I think this setting was enabled by default on syncthing v1 as well. At least on my phone.
Interesting, so you have no problems on your Pixel phone …
I don’t really notice any difference in battery consumption since I disabled the setting. It’s still far too high.
Can’t really say what to look for exactly. But if Synching is draining as much energy as some here indicate, then it must do something - I’d say. So the logs may indicate what’s going on. I’m no expert when it comes to the mobile version, but usually with some traces enabled, the logs are quite useful.
It may be worth checking. In an idle state there usually isn’t too much happening, at least not continuesly.
I don’t know when this started but I only noticed it now: My phone is having trouble reading from its SD card when Syncthing is running…
…But it seems to be because of resource starvation, as opposed to a mechanical failure, because when I stop Syncthing, it functions normally again
Just to be clear, the old version (1.29.6) works on my Pixel 6a with Android 16 with no excessive battery usage whatsoever. This is not a general Pixel/Android battery drain issue, it is definitely something that changed in the latest syncthing (quite possibly in conjunction with Pixel/Android 16).
Actually, just maintaining the connection (e.g. to the discovery server, relays, and other devices) can drain a lot of battery, especially if you’re moving around on a mobile network. I think the main issue is if there is battery drain from the app when Syncthing proper isn’t even running (e.g. because it’s set to work only on Wi-Fi or when charging).
Pixel 6 with latest Android 16 here too, started looking after battery life got cut in half and ended up here. Managed to get the logs for syncthing-fork and syncthing itself, but they don’t show anything repeating endlessly etc. App has an SELinux denied message:
20:01:58W/libsyncthingnat type=1400 audit(0.0:7128): avc: denied { read } …
Syncthing has multiple “Failed to acquire open port“ warnings. I’ll gladly post the logs here, if anyone could confirm I’d not be leaking secrets. Thanks all for looking into this.
I don’t know if I understood correctly but I have no battery problems, as long as syncthing is not active. When Wi-Fi is off (only syncing on Wi-Fi) and syncthing does nothing, battery consumption goes back to normal again.
A bit late to the party, but did you already try to limit the connection count back to 1? This should mimic the v1 behaviour on the network layer.
