A Moto G5 Plus device (Android 8.1.0) was charging and performing normally with a healthy battery response.
One morning, instead of being at 100% (expected after charging all night), the phone reported 61% (unexpected after charging all night). This was with the same charger I always use, which is the one that came with the phone.
Settings > Battery reports that the phone is charging, but the reported charging percent does not increase at all. So if I plug it in at night with 42%, it says 42% again in the morning.
The device is discharging at a normal rate. In other words, given a certain level of charge, and not plugged-in, the battery lasts a normal/long/expected amount of time (many hours with just a few battery percentage points down).
Because of the suddenness and severity of the difference between the former and current observations, the likelihood of this being attributable to simple wear on the battery seems unlikely. That leaves a software problem as a more likely cause.
I read that clearing cache could help, so I tried that by doing the following:
Volume Downand hold a long time until you see the screen have a "weird menu" thing
Volume Downuntil you see
Recovery Mode. You'll see an Android on it's back with a triangle/exclamation mark.
Powerbutton and then press and release
Volume Upthen release all buttons. You should see a list of actions.
Volume Downto scroll to
wipe cache partition, then press and release
Volume Downto scroll to
reboot system now, then press and release
Symptoms seem to persist as before: while plugged in and while the phone reports that it is charging, the percent reported does not increase.
Because I'm an Android developer, I have access to Logcat in Android Studio. I see this reported periodically in the logs:
POWER_SUPPLY_VOLTAGE_NOW=4394353, POWER_SUPPLY_CHARGE_RATE=Normal, POWER_SUPPLY_HEALTH=Good, POWER_SUPPLY_CURRENT_NOW=124510, POWER_SUPPLY_PRESENT=1, SUBSYSTEM=power_supply, POWER_SUPPLY_TEMP=302, SEQNUM=3965, ACTION=change, POWER_SUPPLY_NAME=battery, POWER_SUPPLY_STATUS=Charging, POWER_SUPPLY_CHARGE_COUNTER=3038000, POWER_SUPPLY_CAPACITY=32, DEVPATH=/devices/soc/qpnp-smbcharger-17/power_supply/battery}
This is with the USB cable is plugged into a computer, of course.
POWER_SUPPLY_VOLTAGE_NOW value ranges from 4394xxx up to 4397xxx, indicating the PC is offering a slightly different voltage over time or that the phone reads the voltage slightly different (0.07%), which seems normal.
POWER_SUPPLY_CURRENT_NOW value ranges from 91xxx to 354xxx, but mostly is around 112xxx. This variability probably has to do with how much activity is going on in the phone and whether the screen is on. This also seems normal.
POWER_SUPPLY_TEMP value started at 317 (when I first started logging) to 275 (after an hour). I'm not sure what this change (-13%) means, if anything. Probably because the screen was on earlier in the log and mostly off later in the log.
The rest of the fields seem not to be changing over time.
Knowing that some phones have had issues with getting too hot while charging, I thought that maybe this was an aggressive safety thing that was being incorrectly triggered. The phone was NOT getting even slightly warm when charging, but I thought I'd put it in the freezer while being charged. I put it in the freezer for an hour or two with the cord attached.
After charging the phone in the freezer, the phone did show a higher battery percent. The reported percent was erratic, though. It jumped around from the 90% range to the 30% range. The reported percentage changed as I plugged it into the charger and removed it from the charger.
To reduce the number of programs active during charging, I powered the phone off and left it connected to the PC. Based on the PC's reaction to the USB connection, I can tell that there's still some kind of processing going on in the device, but I thought it might make a difference. The device reported 32% at the start. It indicated that the device was charging.
After leaving the device connected for an hour, it still reported 32%, so the main symptom of this question persisted, even if the charging activity was undertaken while the device was "powered off".
Is there an action or set of actions I can take to get the device to resume normal charging behavior?