interesting. the only variable i can think of is -
battery level higher than X% (95%? 99%?)
in one of the videos above the guy's battery is at 92% - and the notification happens. so the previous theory of 90% does not seem to be true. i still don't like this because often times i throw my phone on the charger at night and my battery may be full or almost full - that doesn't mean that i don't want it charging so that it's fresh in the morning. i ALWAYS want a notification of sweet spot - even if my battery is at 100%!
Yeah I double checked with my Nexus 4 Orb and TYLT VU this morning..... When the battery is fully charged the screen does NOT come on with either wireless charger.... So it has to be some kind of setting in the phone... It won't really matter which Qi wireless charger you have... I don't know yet what the % threshold is but I took mine off the Nexus 4 Orb this morning before leaving for work waited a couple of minutes and placed it back on it and nothing happened.... while still on the Orb I powered it on and it was charging but the screen didn't power on.... So I get to work and instantly throw it on the VU (Phone was still reading 98% battery) screen didn't come on... I just checked it again at 92% remaining and the screen doesn't turn on but it is charging.......... Typically I throw my phone on the Orb at night before bed when the battery is at or below 30% and at work I don't put it on the VU until about 2 hours before I leave for the day (and it's usually around 40% remaining)
Also I don't even know where the "Sweet" spot is on the Nexus 5... with my Nexus 4 Orb I just set it down roughly in the middle of the phone (basically try and put the X in Nexus in the middle of that circle on the hockey puck) and it charges right up.. On the VU it settles down at the bottom so you can't really adjust the phone around outside of Landscape or portrait orientation... but the VU says it has "Multiple" sweet spots for charging a variety of phones.... The VU works just fine with the much larger Nexus 7 as well...... (But the VU at least has a green light indicating it's charging and a red light if something goes wrong on the charger)
Good luck Gekko..... Let me know if you find a better option