Management akumulátorů s ohledem na jejich životní cyklus

Abstract

This bachelor’s thesis aims to familiarize a reader with the issue of battery life, factors that cause its degradation, and how to balance individual cells of battery. The work focuses on lithium batteries. Basic electrical parameters of a cell, which are capacity, voltage and internal resistance are defined here. In connection with voltage and capacity, examples of cell connection are provided. An older battery types were compared to newer types of batteries using energy density values. The thesis then focuses on a comparison of lithium batteries, specifically LiFePO4 and LTO batteries. Furthermore, the factors that accelerate battery aging, including voltage, temperature and charging/discharging rate, are discussed, and their interrelationships are defined. Finally, the differences between passive and active balancing are described, along with various balancing methods. At the end of a thesis, a method for estimating state of health of battery is proposed.