Android get charge rate in milliamps via sysfs

Question

I am developing a informational android app where I want to read the charge rate in milli-amps when the device is charging. I have seen other apps that can do this such as Ampere.

I believe the info should be in directory /sys/class/power_supply/battery which of these files are relevant in accomplishing this, and how could I calculate charge rate in mA from this?

Hamza

Anyone? I can post these file names and contents if it would help. Was hoping to hear from someone who's done this before. – Hamza

You may take a look for this #2440119 – Hasten

Answer 1

directory may change according to the phone manufacturer. See this link for supporting more devices currentwidget

And above API 21+ charge counter and energy counter is implemented: see the doc

Libbie

This appears to be the same value as read from file in accepted answer. Good to know though. – Hamza

sure but as i know the current value file is not the same for all devices. That is why many cases were implemented in the currentwidget app to support almost all devices. – Libbie

Ah I see I missed that part. I apologize this should have received the bounty. – Hamza

Answer 2

According to the linux kernel doc, you can read the charge rate from /sys/class/power_supply/battery/current_now. The value is in µA, so you should scale it by 1000. Negative values mean that the device is charging.

Skunk

Tested this today, this value seems to be accurate but the value doesn't become negative until 20-30 seconds after I begin charging the device. And then when unplugging the device it stays negative for 20-30 seconds before becoming positive. Is this normal? – Hamza