If there was only one concern about the Spro, it was the fact that it uses a rather 'proprietary' adapter to charge it. Unlike most smartphones and tablets, it does not use a 5V micro-USB or USB-C adapter, but a 12V round plug.
In case anyone is wondering, it turns out to be a generic connector: 5.5mm external diameter, 2.5mm internal diameter. The polarity has to be positive (center is positive, sheath is negative). Lastly, it has to be 12V with a least 4A (four amps).
Something like this could work: https://www.amazon.com/Replacement-Adapter-Charger-Benq-Monitors/dp/B003Z6ZR5O/ref=cm_rdp_product and it's a lot less expensive than other third-party ones that claim is specifically compatible with this projector, such as this one: http://www.ebay.com/itm/Generic-AC-Adapter-For-ZTE-Spro-MF97W-1-2-I-II-DLP-WiFi-Smart-Projector-DC-Power-/232062062900
Interestingly, AT&T, T-Mobile, Verizon, nor even ZTE seem to sell the original Spro 2 adapter separately, or at least I don't see it in their Products page, but it's always good to have a spare.