thedarkus, You said you've installed some things, then, uninstalled it. Depending, on how good (or bad) postremoval scripts are, it's possible that some crap remains are still on Your device, even though You "formally" uninstaled it.

My suggestion, would be to do full reflash (even eMMC - not related to case, but will give You a "like new" layout), apply things like repartitioning - if You use it, then, install KP, CSSU, rootsh, and nothing more.

Then, and *only* after such step - no other things installed - re-try powertop test as suggested by freemangordon and vi_.

/Estel