Hello! After being fed up of constantly worrying if my 6S will get me through the day I opted for a smart battery case. It's a great piece of kit and I'm really impressed, I really like the design, it's really comfortable to hold! One thing I have noticed is it seems to take forever to charge. I plugged it in at 4:45 am and at 11:00 am it's only on 80%. Is this normal? Thanks!