We’d like to advise that there is always a conversion loss when the power is sent from a powerbank to the device being charged and this is normal for every charger.
If you’re unsure, here is how to calculate what charge % the Flash Pro and Flash Pro Plus Powerbank can achieve for a specific device.
Let's use an 87W MacBook Pro 15" as an example. The best way to answer your question is using the following formula which calculates the conversion of watt hrs to mah whr = mah/ V*1000*70% (output efficiency at 20V) .
The Flash is 92.5whr/3.7v x 1000 * 70% (efficiency at 20V) = 17500mA.
The Macbook Pro 15" is at 0% switched off whilst charging = 83.6 whr = 22,000mAh = 79%.
The Macbook Pro 16" is at 0% switched off whilst charging = 99.8 whr = 26,972 mAh = 64%
The Ipad Pro 11 is at 0% switched off whilst charging = 29.37 whr = 7,937 mAh = 2.2 times