Syncthing-Fork v2 uses far too much battery over v1

Support Android
48

Yep.

There is even battery drain without configuring anything (see m11kaa’s post #11) …

49

Well if Syncthing drains battery, it’s either caused by CPU usage and/or IO. As it also happens without anything configured and even without the wrapper being involved(termux), this would narrow it down to some housekeeping stuff. We have something like that for the sqlite database but it should be a NOOP most of the time and even more so if the database is virtually empty.

50

I ran syncthing through Termux (fresh config) for a few hours and will attach the generated support bundle. (I think this should only “leak” my public IP, which is acceptable to me :sweat_smile: ). These files don’t mean too much to me right now, but hopefully others will be able to spot irregularities faster. Unfortunately, I did not notice as much of a battery drain, but that is fairly hard to say for sure.

support-bundle-LD2BOGR-2025-10-19T152901.zip (44.0 KB)

2 Likes
51

Ok, I also have this issue

  1. Pixel 7 Android 16
    1. Phone was working great with syncthing fork 1.x
    2. I have set to automatically upgrade with github
    3. At some point github updated to 2.0, battery issues started
      1. High battery consumption on idle without pending uploads or any device connected. On Android Battery: Sometimes 30% sometimes more. Sometimes less but more often super high
    4. Wasted time trying configuration changes
    5. Downgraded to 1.x by using google play version - all issues resolved
      1. On idle consumption is consistently less than 1%
    6. I posted issue on github and my posted was deleted
  2. Pixel 9 Pro on Android 16 (upgraded my phone in late Sep)
    1. At some point google play updated to 2.x and I didn’t notice, battery issues started
      1. High battery consumption on idle without pending uploads or any device connected. On Android Battery: Sometimes 30% sometimes more. Sometimes less but more often super high
    2. Wasted time trying configuration changes
    3. Nothing worked, including removing other devices and fiddling with settings
    4. Very accidentally realized the phone was not on 2.x. Downgraded via sideload - ALL ISSUES RESOLVED
      1. On idle consumption is consistently less than 1% most times it does not even show

It is a bit unfortunate that my post (and some others) are remove from github

Sadly I won’t be doing any upgrades for the time being until good results are shown

Syncthing rocks - really hopping this is addressed

4 Likes
52

Has anyone news on this topic? How could we get better information on the issue? Would it help to file a bug report?

54

I’d like to see how things change with the upcoming release that includes the fix of @marbens

55

which fix exactly?

1 Like
56
57

To be clear, the root cause of this battery problem is still unknown and this fix was not created with this problem in mind. But @akirapink’s comment

does kinda point at one of the issues that was in mind when creating that fix.

58

Folder scanning already has abysmal performance on Android if things are working as intended (thanks Google). I wouldn’t be surprised that this would take its toll on the battery if performance degrades further.

1 Like
59

Alright, this is what I did now:

  1. Installed Syncthing-Fork v2.0.10.2 (fresh setup) on Pixel 6, Android 16 QPDR1 and enabled verbose logging.
  2. Started syncthing 2.0.10-1 (Arch Linux, up-to-date) on my desktop with a fresh config as well.
  3. Shared a folder (from my desktop to my phone), containing an empty text file and a wallpaper picture.

The battery usage went up again (watched Youtube for the better part of an hour just to compare, but syncthing’s battery usage was comparable, even though nothing changed in the folder). I’ll attach the log files.

android.log (2.8 KB)

syncthing.log (94.3 KB)

Please let me know if you need anything else!

4 Likes
60

Here is another case of excessive battery usage since upgrading to v2.

I have a Pixel 8 with Android 16 and it is clearly related to Syncthing running. I was on a week of vacation the other day and intentionally did not connect to any WiFi during this time (Syncthing is limited to running only when connected to WiFi) and I would get over 2+ days with my battery.

When I am at home and phone is connected to WiFi all day and thus Syncthing is running all day I hardly get over one just a single day.

1 Like
61

I’m using syncthing-fork 2.0.9.1 from F-Droid on a Pixel 7 running latest GrapheneOS (Android 16).

I’m experiencing the same problem as described in this thread. The issue was not present in the 1.x version of the app.

As suggested above, I tried setting the sync to a schedule (syncing for 5 minutes every 60m). I just noticed Syncthing still ate 95% of my battery today according to Android’s settings. It says the app was active for 46m over the last 14 hours.

Interestingly AccuBattery claims Syncthing ate only 0,1%, but I don’t know how much this app can be trusted in regard to this topic.

62

I’m using syncthing-fork 2.0.9.1 on Pixel 8 with Android 16 and face also battery consumption in the 2digit range, e.g. 30% today. Conditions are:

  • Syncthing
    • WLAN only
    • Android energy saving: not checked
    • Start w/o network: not checked
    • sync with timeschedule: not checked
    • sync-cycle: 5 minutes
    • sync-pause-interval: 60 minutes
  • Android
    • Background usage: enabled, optimized
  • Peers
    • syncthing-macos 1.30.0-1
    • v2.0.11, Linux (64-bit Intel/AMD)
63

To everyone that it concerns, the release that contains the fix mentioned by @bt90 is out. Again, don’t get your hopes up that this fixes it, although I’d be interested in your feedback whether it does resolve the problem or not.

3 Likes
65

Pixel 7 Pro

WiFi 6 all day

10 shared folder

3 nodes all in network

52% battery yesterday with very small files added to/from share folder

Version:

v2.0.11.1 from GitHub (Obtainium)

Two days ago, same scenario:

v2.0.10.2 from F-Droid

~43% battery

10 shared folders, 7 are shared between all three nodes.

did not have this issue on 1.30.*. That version’s been purged from both GitHub releases and F-Droid so I can’t even go back to a version that used <1-2% of my battery.

debian 13:

node2: syncthing v1.29.5 “Gold Grasshopper” (go1.24.2 linux-amd64) debian@debian 2025-04-20 21:21:27 UTC

fedora 43:

node1: syncthing v1.30.0 “Gold Grasshopper” (go1.25rc2 X:nodwarf5 linux-amd64) mockbuild@fedora-koji 2025-08-17 00:00:00 UTC

i update these via apt and dnf, respectively. The android version is way ahead of the packages I have on these nodes (1.30)

is this version mismatch between nodes related? i’d prefer to stay on the same version across my machines, but it’s impossible to use 1.30 on my phone through my two normal channels, F-Droid and GitHub RSS.

66

Today I deinstalled syncthing-fork 2.0.9.1 from Google Play Store and moved to v2.0.10.2 from F-Droid. Battery consumption today is now 4% :smiley:

Conditions same as posted in https://forum.syncthing.net/t/syncthing-fork-v2-uses-far-too-much-battery-over-v1/25384/62?u=george_hi

67

I didn’t do a fresh setup but for me there was no change in battery consumption. Currently waiting for 2.0.11.1 to arrive on f-droid.

Is some Pixel user using a custom ROM like GrapheneOS or are all of you on Stock Android? I could imagine, that there might be less problems since other brands don’t seem to be affected as much as well. I am on stock right now.

68

Update: Today battery consumption is at 54% (00:00-19:00). Looks like the issue is not fixed for my setup. :anguished_face:

1 Like
69

I had a similar experience as @George_Hi the other day when I did a change in Syncthing (I removed a stale node that is likely to never come back online again). On that day battery consumption was back to 1.x amounts - but the next day the enormous consumption returned.