Estimated Power Consumption

Understanding the power consumption of EV charging sessions is crucial for both station owners and users. It not only helps in setting competitive rates but also informs future infrastructure improvements. EVnSteven is designed to provide these insights without the need for expensive hardware.

There are at least three ways to estimate power consumption, but one involves costly hardware. While this method is the most accurate, it is often unnecessary. Instead, EVnSteven offers two better and more cost-effective methods that do not require any hardware.

The first method calculates power consumption based on time. At low power levels, the power delivered is practically constant for the entire session. For Level 1 and Level 2 stations below 30 amps, the formula for calculating power consumption is:

Power (kW) = Energy (kWh) / Time (h)

The second method relies on the user reporting their state of charge before and after each session, as well as the size of their battery in kWh. This method is also quite accurate:

Power (kW) = (Starting State of Charge (kWh) - Ending State of Charge (kWh)) / Time (h)

Both methods consistently yield similar results, with a variance of +/- 2 kWh, which translates to a cost difference of about 50 cents. This small price difference is a reasonable trade-off for the convenience of not having to install expensive hardware. These numbers are based on our tests of a 40 kWh battery and a 7.2 kW charger.

By providing these estimates, EVnSteven helps station owners set competitive rates while ensuring profitability. Users, on the other hand, gain transparency regarding their charging costs. These benefits make EVnSteven a valuable tool for managing EV charging infrastructure efficiently and effectively.