Hey aseb - I just recently installed a 500 watt rearhub motor with a 20 amp controller powered by a 36 volt 10ah lifepo4. I have been putting it to the test in these ozark mountains and am amazed at it's power. If you have a 36v 20ah battery already, just get a brushless hub motor,controller and whatever wirng & bracket set-up you'll need and swap it out. I'm not familiar w/powabykes, however "where there's a will there's a way"- goodluck