Iphone won't charge completly

Hello,

i've got a question about charging the battery.

I just bought the iphone 5s and as a daily routine i plug my device every night.

The last days i just realised that the battery isn't at full capacity in the morning

The battery indicator just shows something between 96% and 98%.

Now my question is, if that's normal or should i call the support, because i never

saw anything like that with previous phones?

Sorry for my bad english 😉 and thanks in advance.