I doubt that there is any way to determine the power consumption of lights in blinking mode. There are a number of reason why, including the circuit efficiency itself.

The whole "charger" total mA measuring is bogus. The display only reflects the current drawn into a tube of electro-chemical paste - not an actual expression of power consumption - as in light.

The larger costs of of using these products lays with the energy consumed during manufacture and the chemical wastes associated with the technologies surrounding them. I would suspect using a generator could be an increase in efficiency - but that's a guess as well.