My iPad is about 4 years old. The battery goes from full to empty in about 2 hours now. My iPhone was the same and I got a new battery but it didn’t make it much better so I got a new phone. I can’t afford to replace the iPad at the Moment. Is it ok to keep it plugged in on charge more or less permanently? I’ve googled and can’t seem to work out if this is safe to do. Does anyone know the answer?