If it doesn't turn on with a charged battery, you may have a broken logic board. If you're out of warranty, somebody has to open the device and replace the logic board. The part is available on ebay. On youtube you will find a guide on how to disassemble an Acer tablet.
Maybe a tech savy friend can do it for you. If you want to pay to have somebody do it for you there are third party Acer Tablet Repair Services.