Hi there i'm a small business owner and as a low cost method of keeping tabs on my fleet of vehicles I fitted them all with android phones so I could track them on Android device manager... They are cheap phones (vodafone models) but nothing is installed/enabled on them including play store or any other unnecessary apps. The problem lies with the phones seemingly constantly coming up with messages asking to be logged back into the google accounts, and while these notifications are on screen, until i've manually logged back into the google account, I can't track my vans as i get location unavailable. I have 9 vans and it's happened to about 7 of them and some of them more than once. The phones are bolted in custom cases to the dash and the drivers use them for calls to the office only (i monitor the contract sims as well). What could be causing this and how can I stop it?