Analysis of CT-CV Charging Technique for Lithium-ion and NCM 18650 Cells

Battery Technology is ramping up these days with enormous boost in electric vehicle (EV) and hybrid electric vehicle (HEV) industry. One of the promising and crucial in batteries is to provide safe and quick charging algorithms. An extension of constant temperature and constant voltage (CT-CV) charging technique is studied in this paper, with a battery under test (BUT) of chemistry type Nickel Manganese Cobalt (NMC) 18650 lithium-ion cell. The analysis of the charging time, and surface temperature rise along with the PID controller gains used is performed at ambient temperature of 20°C. The performance and surface temperature analysis during charging and also discharge can be seen in this paper. In addition, the experimental setup is explained in detail with emphasis on the implemented CTCV algorithm. Also, the CT-CV charging technique implemented is compared to the standard constant current and constant voltage (CC-CV). By the end, the experimental results on tests performed with NMC cell is presented.