Testing the reassembled Powermonkey under various loads proves instructive:
The relatively low capacity at 100 mA (black) shows that the boost converter isn’t particularly efficient; the discharge time is long enough that power loss in the booster outweighs the cell’s higher capacity at lower loads.
Surprisingly, the voltage drops to 4.5 V at 500 mA, which is what you should get from a typical USB port. If the device you’re charging expects the nominal 5 V at 500 mA, it will be sorely disappointed. Admittedly, that’s only 10% low, but …
The booster produces only 4.0 V at 1 A, with odd bumps as the cell discharges. Huh?
I know for a fact that my 1.8 A @ 5.0 V Kindle Fire doesn’t even notice it’s plugged into the Powermonkey. The voltage is probably too low to trigger the “External Power, Ahoy!” signal.
Bottom line: it’s not clear this thing actually works for contemporary devices. Maybe newer Powermonkey products behave better?
The Smell of Molten Projects in the Morning 
hack dat mcu and give it more BOOST less BUCK
speaking of bucks, hopefully it was dirty cheapness…
Might be a cheap chinese PWM, smaller resistor on an input and Voila’
>:-)
I could fiddle with it, but it’d require dismantling the PCB and scraping off all the foam tape goo… and I doubt it’s worth that much effort. [mutter / grumble]