Iron Sleep

[drsage]

I have set the timers for what seems appropriate - go to sleep after 6 minutes and the motion sensing for 10 units.
I let the iron sit for 6 minutes and most times it tries to go to sleep but immediately wakes up again. Rarely it will sleep.
I tried setting the motion setting for something like 25 and the next time it did sleep it took a LOT of shaking to wake it up.
The iron is connected to a 65 watt battery power bank and runs at 20v. It acts the same on a 9v capable wall wart.
Any suggestions for appropriate settings? or maybe the motion sensor is defective??