I have an iPad 64 3rd gen. When I plug in the iPad to an electrical outlet it always says "not charging" on the icon on the iPad, yet it seems to charge, though very slowly. I have tried 3 different cables and two ac connectors with no change. Also when I connect it to the computer it also says it isn't charging. I am always careful to close out any programs I had used earlier so there is less drain. Any suggestions or explanations would be appreciated. Thank you.