If you wonder what you can use to charge your SmartSleep, please read here if we can answer your questions.
Charging the SmartSleep device
You should only use the supplied power adapter provided for your SmartSleep device.
A battery pack, laptop, iPad charger, car phone charger do not provide enough power to charge the device properly. It might not charge at all, or not fully charge your SmartSleep device, resulting in an underpowered headband.