I have a Smt580 tablet. Galaxy tab A. I haven't charged it in to long. It it is showing the battery icon shakely on the screen as I'm now charging it. Its not now showing percentage numbers as well to show its progress. I wonder if its got say 2% in hardware terms left say in the battery for example only enough to show a literol icon but not a percentage charging feature. Bare bones of power might not charge the battery back ever. Any ideas. I'm not that tech minded but suppose that there's either a minimum point you can't return it from or it goes dead entirely. Any ideas to jump start it? The charger is fine with this phone for instance and seemingly is with the tablet but not true charging taking place probably. It won't switch on whilst plugged in or removed. Is it a sealed unit so I can't buy a new battery? Thanks.