Algorithm for fast determination of LiFePO4 battery nominal current

The development of production and increasing usage of light electric vehicles such as electric bicycles and electric scooters entails development of batteries, battery chargers and fast charging algorithms. Batteries with different nominal electrical characteristics and production technologies are currently in use. Among them, lithium-iron batteries are increasingly being used. The differences in basic characteristics of batteries and standardization issues require fast identification of various battery types and adapting of charging algorithms according to nominal current, voltage, capacity and state of charge. This paper describes a method for determining the nominal current for unknown LiFePO₄ battery connected to the stationary filling station for charging electric bicycles. A prerequisite for determination of the rated current is identification of current-voltage curve at the moment of connection and identification of the number of cells. The algorithm for determining these parameters is given in the first part of the paper. The second part deals with determination of the nominal current for LiFePO₄ battery based on current-voltage response to the selected battery charging algorithm.