Some customers (less than 5%) has battery drain issue for iPhone.
Apple confirmed this issue and we work together for fix it.

Anyway we did following procedure and never got this issue:

1. Setup Airplane mode. (if your device doesn't have Airplane mode: just turn off Wi-fi).
   Important - do it BEFORE! next step
2. Reboot device.
3. Start EasyWakeup.

Yes, we know it's not cool to reboot your iPhone, but we update this post when we will find some another solution of this issue.