[C2] Battery limit does not prevent phone from charging to 100%

Bug Reports
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1

REPRODUCIBILITY: depends? (battery limit may have actually worked once or twice, but it’s too hard to tell for sure)
OS VERSION: 5.0.0.77
HARDWARE: Jolla C2
UI LANGUAGE: English (United States)
REGRESSION: probably not

DESCRIPTION:

Battery limit does not prevent the battery from charging to 100%.

While using the phone the battery hit 90% and I got a notification saying “Charging complete“ but charging continued.

I only saw that notification once because you can only see it when you are actually using the phone (doesn’t show up in Events View) but many times when I checked the percentage it was at 100%.

When searching the forum I could not find anything similar to this, so I don’t know for sure if this is actually a bug in SailfishOS, but I have no idea how I could’ve broken the battery limit.

PRECONDITIONS:

Enable battery limit in Settings > Battery

STEPS TO REPRODUCE:

  1. Enable battery limit

  2. Charge the phone

  3. Notice that the battery charges above the battery limit

EXPECTED RESULT:

Battery stops charging at specified limit.

ACTUAL RESULT:

Battery charges above specified limit.

MODIFICATIONS:

OpenRepos: Yes

Patchmanager: Yes

Chum: No

ADDITIONAL INFORMATION:

I can provide logs if needed, I don’t know where to find them though.

1 Like
2

I use Battery limit on C2, too. I’m charging nearly every night. I had the described issue around every few weeks (with 80% and 90%, if remember correctly).

3

I could imagine that it’s necessary to charge the battery sometimes to 100% to keep the calibration up to date. So this is more like a feature and not a bug.

4

I have the limit set to 90 % on my C2 and never experienced this until now…

5

My C2 did that by itself sometimes. That is intended behaviour by firmware.

To OP (@aerowrap) so the bug would be real if limit is not respected most of the time.

6

With these settings, my Jolla C2 has been working flawlessly for weeks. If you also install the “AIDA64” app, you can

Screenshot_20260505_090636_001
Screenshot_20260505_090636_001720×1600 101 KB

Screenshot_20260505_090733_001
Screenshot_20260505_090733_001720×1600 245 KB

verify this under “Battery”.

7

Absolutely agree with this and I wondered myself if that’s a bug since on Xperia 10III this never happened. For me too one two independent C2 devices with charging limits set, they sometimes would change to 100% even though the limits are set to 80%. Also charging to set at max. 90% still was overruled in one occasion when the phone was switched off.

8

Originally I thought that if you charged the phone to whatever the battery limit is and then the next time you only charged it to like 70% after that it would charge to 100%, but why would the “Charging complete“ notification pop up then?

And if that is actually the case, I have never seen anyone else besides SailfishOS do that. I don’t know much about batteries so maybe doing that actually helps the battery, but I doubt it is for calibration.

9

Good practice for lithium type batteries is ocassionaly fully charging even if limited otherwise.
Android does that for sure. Others most probably too.

In practice it looks that limit is respected most of the times. But sometimes charging goes to the ‘100%’. That % is relative anyway. Some define 100% lower to prolong battery life. There are many things that influence 100%. It’s just orientation anyway.

In general deep discharge is also bad for the lithium type battery. So limits are good despite relativity.

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