If you want to run your system without a wall outlet this guy has you covered. There are very few USB type C battery banks out there as they are cutting edge right now.
This one is specially selected for Audio Ape 2.0. Designed to never sleep and provide a whopping 10,000+ mAh. That will charge an iPhone up to 3 times and an iPad mini twice. Do not use normal USB battery bank, it will not support an Audio Ape 2.0.
You need to have a native USB C output that this battery bank has as well as a high amp rating of 3A.
Additionally, it has a standard USB out so you can use it on other devices if needed. You can charge this battery bank with either USB micro or a USB C cable.