Some details are available in this article. Wu, X., Freese, D., Cabrera, A., & Kitch, W. A. (2015). Electric vehicles’ energy consumption measurement and estimation. Transportation Research Part D: Transport and Environment, 34, 52–67. doi:10.1016/j.trd.2014.10.007 

https://www.researchgate.net/publication/267928696_Electric_vehicles'_energy_consumption_measurement_and_estimation

https://ieeexplore.ieee.org/document/7001349

Sensing:

Weight

Inclination

Torque

It is simple. The type of battery and its voltage and capacity. The battery rating will decides current. e.g. for 100 AH battery of 48 V, current is 2 Amps. Hence energy demand is 100X48=4800 say 5000 wh or 5 KWH or units.

Instantaneous power depends on operating conditions. Whereas max power and continuous rating power can be defined.

I use to work with grid analysers and power meters. If required, use current or voltage adapters to suit the magnitudes.

For a precise metering check if there is a PWM and make sure that the sampling frequency is high enough to not be affected by such a bandwidth.

For std 230V tests, you can replicate tools as simple as this: https://youtu.be/aDQtart2U8E

If you need instantaneous values, you can use the Max/min functions and/or read from the RS485 port. Otherwise, for higher sampling frequencies, I used to work with a National instruments DAQ. Or a properly configurated Dspace could also be suitable. Your choice.

Cheers

There are commercially available electricity meters for this, which can then be added to every charge. And ultimately can also run an evaluation. There is nothing simpler here. This power consumption depends, of course, on the time the vehicle is used. That is, in winter an EV vehicle requires three times as much power as in summer and a few customers.