Capacity suddenly drops to 0

Here is another graph when this issues is reproduced again.

It shows the problem with upower history (orange) not containing enough data to generate a graph corresponding to the actual capacity of the device (which confuses users a lot)

Then it shows over the last hour the effect of the adjustment function in the battery driver when the capacity (in purple) drops quickly from 21% to 0% then oscillates between 0 and 1 for 30 minutes until the device really dies (device was at 0% when voltage reached 3.4V then shutdown at 3.0V)

Now, there are the following possibilities:
1. The battery meter returns wrong data to the driver (calculation of the capacity is incorrect for example)
2. UI_SOC and SOC diverge and the adjustment is not triggered.
3. There is a battery calibration or a battery profile issue

ods containing the data.

Here another graph produced by reproducing the test case on arale which exposes the HW fuel gauge through sysfs.

This graph shows that the capacity returns by the battery driver and the capacity returns by the battery meter are the same. THat would eliminate the case where the battery driver and the fuel gauge are diverging.

The voltage graph shows that voltage decreases linearly for about 14 hours, then decreases faster and faster for 4 hours until it reaches the lower limit of 3.4V and the devices shuts down.

When it reaches 3.5V the percentage starts dropping to reach 0% in half an hour.

3.5V corresponds to the value of low power wakeup (and 3.6V for the normal wakeup)

The battery meter table shows that 3.6V also corresponds to a DOD of 97% at 25°C, although the percentage reported by the fuel gauge is still 20% while it should be around 3%.

data file.

It's normal for voltage drop off to accelerate below 3.6v (or 3.7V, depending on the battery). The voltage discharge curve looks normal for lithium ion. However, the capacity graphs look like a pretty poor method of converting voltage into a percent.

I find that the kernel's reported voltage usually tracks the actual voltage pretty closely, but the capacity estimation lags way behind. This is harder to measure on krillin since its kernel doesn't report voltage.

In any case, I doubt it's hugely important for the reported percentage to be totally accurate. It's more important for the voltage to give timely and continuous feedback about the battery state, with no large sudden jumps. Being reasonably accurate likely only matters near the top and bottom of the scale.

The description in bug 1550223 confirms the same behaviour but in power charging mode.

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In the last few weeks it has quite often happened that my Krillin would turn off while the battery indicator was still showing a good 15-20% battery.

Today, after the device switched off, I plugged it to a wall charger while it was off.

Here's what happened:
1) Phone switches on and goes to charging screen (showing the fullscreen charging animation), showing 26% battery
2) After one minute, the battery animation was showing 18%
3) After a few seconds, it was showing 17%
4) After a few more seconds, it was showing 15%
5) After a couple of minutes, it was showing 2%
=====

It reinforces the suspicion of a faulty PMIC Fuel gauge as YC Chen originally suggested in bug 1471913. However no one confirmed that the proposed workaround improves the situation.

For reference the workaround was:
1. set the phone to airplane mode
2. charge overnight.

Read Bug #1550263 (not 1550223 )

Charging with airplane mode did not help.

I had the same issue this morning. The battery was not even red, and after a few minutes I grabbed the phone and it was dead.

More info: I went to bed with 97% battery, when I woke up it was still 97%.

It sounds a bit too good to be true :) these smartphones usually use 0.5 or 1%/hour, so it should have gone down by 3-4% at the very least

the battery level I reported is the one I got from the UI, so power-indicator

@Andrea, right, this is another issue and part of bug 1538470. upower doesn't update its history records when the device is suspended but the capacity reported by the kernel and the PMIC is correct.

This bug report is about the wrong capacity reported by the kernel when the battery is close to empty (~3.6V)

Update:
After the phone died on 29th I left it charging until 100% while it was OFF.

I could not reproduce the bug this time, the

Nothing changed on my device, except I enabled a data plan (that I didn't have during the previous test). Enabling the data plan may have led to considerably faster discharge, so the conditions of the test are not exactly the same, but this time everything worked fine. It's still at 5% battery now.

I tried to completely discharge the phone and charge it while turned off twice without success. I am still observing this behaviour which was introduced by some OTA. I cannot remember which one was it.

see also https://bugs.launchpad.net/canonical-devices-system-image/+bug/1458756 (which maybe should be closed in favor of this here)

Same problem here. Today reported to be at app. 50 % battery, then suddenly my phone is dead.

same on mx4/rc proposed, since forever X-)