My iPad is approximately 5 years old, it is only for the past year that it has been used as my main computer. Nowadays it takes up to 9 hours to get it to fully charge. I use the same charger for my phone and it takes a couple of hours maximum. I have looked online and cannot fathom whether I can put a new battery in the iPad. Maybe at the age it is would I better buying a new one. Any thoughts please.