Hi. I have had my Q500 4k for a year with no problems. I had not used it for about 3 months and when I did so, I got the 'dreaded' vibration and low battery warning after only 2 minutes of flight. I tried 3 batteries, all the same effect. When I checked them with a battery checker the voltage was around 11.6v after the flights. The batteries are obviously OK but for some reason the ST10+ is showing them as being discharged even though the start up voltage was about 11.6v. Any ideas please?