Question mark in the battery icon on the smartphone Android Motorola

One of my Motorola Droid 4 yesterday decided to make me a little nervous, the phone in question has been purchased a few months ago in new condition, it has always worked perfectly, the battery is always lasted almost three days but always had a small problem with the GPS, to make the fix satellites he needed tens of minutes, a strangest thing considering that the other Motorola Droid 4 in my possession perform the fix of the satellites in just seconds.

Yesterday, however, the phone had a very strange problem, the battery drained from 70% to 30% up to turn off in a few minutes and plugging it to the charger the phone did not wanto to charge, it did not start and in the battery icon there was a question mark. To be sure that was not a software problem i restored the phone at the original firmware using the factory cable, a cable that bypasses the battery directly powering the phone, but the problem was still there. Considering that powered with the factory cable the pohine did work without problems i realized that the problem was just the battery, the phone did not recognize anymore it, really strange because the battery was in good condition.

From some time Motorola many of its phones with non-removable battery and the Motorola Droid 4 is one of them, in fact the battery is not really not- removable because its contacts are simply screwed in the motherboard with screws Torx T5(*) and my thoughts immediately turned toward them, could the contact screws have loosened?

I then removed the back cover, lifted the protective sticker near the battery contacts, removed the rubber seal, I better tightened the screws, I plugged the phone to the charger and the battery was again recognized and charged without problems, beyond this the GPS also has started to work properly fixing the satellites in few seconds.

Strangely, the screws were always loose, and for this the battery did not provide the appropriate power to the GPS for a correct operation until the screws have not been able to ensure more even the slightest contact to the battery and prevent the recognition.

The strange thing is that everything is done on a new phone, never opened, but so be it.