Вот: https://www.reddit.com/r/RocketLab/comments/4epbzd/on_using_electric_motors_powered_by_batteries/
Reading that the Electron will use battery powered fuel pumps got me thinking if that was efficient given how low the energy density of batteries are. Doing some quick napkin calculations produced the following:
F1 engine 6770kN thrust and 41MW turbo-pump = ~6kW/kN pump power per unit thrust.
For the 1st stage of the Electron that translates to 6kW/kN x 183kN = 1098kW
With ~160 sec burn time from full duration engine test that requires 1098kW x 160/3600hr = 49kWh.
Lithium Polymer batteries have energy densities up to 265Wh/kg = 185kg battery.