Battery status problem - status jumps wildly

Help Fairphone 5
,
1

For a few days now, the battery status of my FP5 jumps wildly between 0% and 100% without any obvious reason.

Sometimes, it doesn’t even display a percentage, but rather just a “?” as if the device could not tell the battery status.

And even when charging it while turned off, the charge indicator may display 0%, 100% or the actual charge. And again, these jumps between values happen seemingly randomly.

This even results in the phone spontaniously shutting down, when it suddenly reads the battery as 0%. And it can also obstruct the booting process so that the phone is suddenly off again while bootup up.

The jump to 100% also resets the statistics everytime, so it then always looks as if I had just fully charged the phone - which I didn’t, it simply jumped to 100% for no appearent reason.

Here are some screenshot of what this looks like, while the phone was NOT charging:

“?” as battery status:

Screenshot_20260831-155934_1
Screenshot_20260831-155934_11224×1860 60.5 KB

In the top right it says 100% while at the same time, below it says 88%, indicating a sudden jump just a few seconds ago:

Screenshot_20260831-155932
Screenshot_20260831-1559321224×2700 156 KB

What I tried so far:

  • completely drain battery and fully charge it while the device is turned off
  • turn off, remove battery for 30 minutes, put it back in and turn back on
  • combine the points above

None of this seems to help.

Also, in case this might be related, I already had the problem that whenever I reboot the phone, it would power off as soon as the home screen came up, because the battery was considered to be 0%. I had to remove the battery and re-insert it and boot again in order to prevent another immediate shut down.

It seems like a defective contact somewhere in the hardware. Did someone else experience this or has any idea, what this could be or how to fix it?

2

Hello
How old is the battery? Could you check it for any swelling?

3

The battery does not appear to be swollen anywhere.

It is the original, which came with the phone. I bought the phone in November 2024.

4

Hi
Thanks for getting back to me.

My three year old battery is working fine so I would expect yours to keep up, but from where I sit, its either the issue with the device or battery.

If you have a local Angel nearby you might try to see if they have a battery to check. Otherwise you might consider ordering a spare and seeing if it makes any difference. There is some internal testing available for battery, that is my result (for my second newer battery that I use for travels)

Screenshot_20260905-150051
Screenshot_20260905-1500511224×2700 110 KB

If is hardware, and you would need to send in the phone, now is the last moment for full backup:)

5

Below are screenshots of the results of my battery test:

Strangely, I cannot press the “PASS” button. I don’t know why.

Charging:

Screenshot_20260905-182756
Screenshot_20260905-1827561224×2700 81 KB

Discharging:

Screenshot_20260905-182801
Screenshot_20260905-1828011224×2700 82.1 KB

6

Hello, I observed the same phenomenon. As far as I can tell, this is a software issue, not hardware. I have two batteries - one originally shipped and a spare battery. Neither of them is swollen. With both of them the phone shows the same problems. Additionally to the erratically jumping SoC percentage, I observed the following : after a soft restart, the phone measures 0% SoC and immediately shuts down again. I then have to remove the back panel and the battery, put it back in (after one second) and then the phone works again and the battery index shows a plausible number. I don’t need to charge it to fix the issue, so there should be no problem with the battery

7

To me this reads rather like a hardware issue. “Some” hardware component is not able to measure the voltage of the battery reliably anymore and then software gets wrong values and does what it is programmed to do, e.g. shutdown if the battery seems to be low. Therefore I think it doesn’t make sense to hope for any software fix for this issue, unfortunately.

8

Makes sense. Makes it hard to fix - neither new battery nor software updates can help. If it’s the case as you describe, it would require some neat little sensor or so to be replaced… So we probably need to live with the issue… Fortunately it is not a big deal as long as you know that 0% battery is not a reason to panic :sweat_smile:

9

However, this negatively affects the charching process. If “Battery Protect” is enabled (thus charging only up to 80%), the charging process stopps when the battery glitches to 100%.

As far as I remember, it is not good for the battery to plug and unplug the charger all the time. And these glitches have the same effect.

10

But both of you could also just contact support and let them fix it for free? Don’t know when you bought it, but the extended warranty from the earliest FP5s sold lasts until September 2028, so you got plenty of time to get it fixed within

11

I would disable battery protect, use the phone till the battery is empty and phone shuts down. Let it off, charge in one step till 100%. Recalibrate the battery.

12

As described in my OP, I already tried that. It doesn’t solve the issue.