I emailed the company to ask about it. This was their response:
Thank you for your interest in the ChargeTech Portable Power Outlet. Unfortunately we are not able to provide performance estimates due to the vast variety of devices and their technical specifications. The performance yield of the Portable Power Outlet will ultimately depend on your particular device's power draw. I have attached the manual for the specs of the units for your review.
We currently offer Portable Power Outlets in 3 capacities:
12,000mAh (AC output voltage of 120V AC; Continuous AC output 65W)
18,000mAh (AC output voltage of 120V AC; Continuous AC output 85W)
27,000mAh (AC output voltage of 120V AC; Continuous AC output 85W)
The difference between each amperage is the amount of time your Portable Power Outlet can withstand powering your device. The charging time will depend on the amount of power the unit you are charging draws from the Portable Power Outlet. For best results, the device you are powering should stay within the Portable Power Outlet's capacity limits.
We hope one of these options will be an option that will fit your needs. If it doesn’t, please keep in mind that we offer a 30-day Risk Free trial purchase.