  The heterogeneity in pack voltages and capacity of aged packs limits the
performance and economic viability of second-use battery energy storage systems
(2-BESS) due to issues of reliability and available energy. Overcoming these
limitations could enable extended use of batteries and improve the
environmental impacts of electric vehicles by reducing the number of batteries
produced. This paper compares Lite-Sparse Hierarchical Partial Power Processing
(LS-HiPPP), a new method for power processing in 2-BESS, to conventional power
processing architectures using a stochastic EV charging plaza model. This
method for performance evaluation allows a fair comparison among power
processing architectures for 2-BESS. Results show that LS-HiPPP increases the
battery energy utilization to 94% as compared to 78% for conventional partial
power processing (C-PPP) and 23% for full power processing. These results were
obtained with 25% heterogeneity in individual battery capacities and 20% power
processing within the 2-BESS. Derating and captured value are two derived
performance metrics for comparing LS-HiPPP and C-PPP in this work. The derating
for LS-HiPPP is 84.3% in comparison to 63.1% for C-PPP. The captured value for
LS-HiPPP is 79.8% versus 51% for C-PPP.
