Effects of pulse and DC charging on lithium iron phosphate (LiFePO<inf>4</inf>) batteries

Abstract

Resonant converters which use a small DC bus capacitor to achieve high power factor are desirable for low cost Inductive Power Transfer (IPT) applications but produce amplitude modulated waveforms which are then present on any coupled load. The modulated coupled voltage produces pulse currents which could be used for battery charging purposes. In order to understand the effects of such pulse charging, two Lithium Iron Phosphate (LiFePO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) batteries underwent 2000 cycles of charge and discharging cycling utilizing both pulse and DC charging profiles. The cycling results show that such pulse charging is comparable to conventional DC charging and may be suitable for low cost battery charging applications without impacting battery life.