Connecting the Neopixel strip to an Arduino is quite simple and only requires ... My future project will be battery powered, so I am not very worried about 3.5amps right now.

Each digit is made using one pair of Neopixel rings ... of the build is pretty plain vanilla — an Arduino Nano clone, a DS3231 RTC, a Lithium battery, and some buttons, all housed together ...

Arduino developers and hobbyists looking for a portable battery shield to powered their projects might be interested in a new shield called the EnergyShield Arduino rechargeable battery.