Original charging fee formula: Service charge (30/50 yuan per time) + electricity charge * exchange number of times = final exchange cost. The service charge is irrelevant to the exchange number, so users will try to run out of battery power when exchanging, which will cause car owners to be unwilling to exchange at 20% or more of their battery power, resulting in some inconvenience and lack of flexibility.

E = (P × T) / (η × t)

Where:

E = replacement cost

P = power consumption of the equipment

T = total running time

η = efficiency of the equipment

t = time period for which the electricity is charged

Plan 1: Basic service fee (9.9 yuan/time) + (electricity charge (current electricity price) + service charge (current service price)) * degree = final exchange electricity cost

Plan 2: Replacement cost of electricity = Total unit price of electricity (electricity fee (time-of-use electricity fee) + service fee (time-of-use service fee)) * amount of electricity replaced

When the electricity obtained does not reach the set minimum exchange electricity (20 degrees), it will be charged with a service fee corresponding to the minimum exchange electricity, and the electricity bill will be calculated according to the actual electricity obtained.