UC Davis Institute of Transportation Studies

The use of ultracapacitors in plug-in hybrid vehicles (PHEVs) with high energy density lithium-ion and zinc-air batteries is studied. Simulations were performed for various driving cycles with the PHEVs operating in the charge depleting and charge sustaining modes. The effects of the load leveling of the power demand from the batteries using the ultracapacitors are evident. The average and the peak currents from the batteries are lower by a factor of 2-3.