Android read battery capacity

Hello

I'm developing a little android APP.
I want to read Battery Capacity..
As far as I know is there no API before API Level 21 for that.
So I did it with the system file: /sys/class/power_supply/battery/full_bat.
This works great on the HTC One X/Sensation. But not on the SGS 5 mini...
Unfortunately I don't have an SGS 5 mini myself...
So I ask you. Is there an other way to read battery capacity?
Or can you give me the path to the system file on the SGS5 mini?

Thanks for your help!

PS: If you're interested in my app. Search on the playstore for charge cylce counter:angel: