I would ask if you can see any battery level indicator while charging the tablet turned off.
My model is the tab 8w and I can see the battery level for a few seconds. Then it disappears and there is no way to see it again. Usually for a device we expect to see the indicator by slightly pressing a key.
I've contacted my local support, and sorry to say, after I've asked it 3 times, finally got a call back. The support at first sight was a bit confused, confirming the need to press a key to do it.
Then admitted the issue and added that is a problem related to windows 8.1 .
I can't see any point for microsoft to do that, why should the indicator appear and disappear?
I've read somewhere (I think here but I can't find it again) about an acer android user reporting the same issue, si it looks like it's an acer problem, not a software one.(and this explains why I asked it to any windows tablet owners)
The way to follow are:
- charge the tablet and leave it plugged for some hours (more than needed time)
- charge the tablet turned on (more time to charge it)