hi, I am also experiencing the same exact issue with my Radcity 5 Plus.  The power stays on as long as the lights are on, but once I turn off the light, the power goes away.  This was not the case when I first got the bike and only became like this in the last day.  I have only had the bike for the past couple weeks.  Have you guys reported the issue to RadPower?  Any feedback?  Thanks