Hi
Thanks for your quick reply.
I now think it must be a problem with my charger which I replaced here in Malaysia. I was told it was an original Apple charger but perhaps not, although as it shows the charger indicator on I assumed it to be working correctly.
It may be an apple charger but for an iPhone which is half the charge or it could just be a knockoff. But even then it should have charged more than this overnight. It may just be registering a charge and that is all.