Powertrain electrification encompasses hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and pure electric vehicles (EVs). All vehicle types are being intensely investigated for cost-effective solutions for reducing emissions with a focus on Hybrid Heavy Duty Vehicles (HHDVs), mainly for purposes of fuel consumption reduction, which is of the utmost importance for the commercial vehicles business sector. This research examines the cost of automotive Li-ion batteries in comparison to that of the mainstream lead-acid type. It is shown that although there is an accumulation of a higher upfront vehicle cost, the cost of ownership is greatly reduced compared to that of lead acid batteries, with a cost of 0.045€/kWh/cycle and 0.051€/kWh/cycle, respectively, based on the cost of each battery type considering the total number of discharge cycles that can be endured within a lifetime. It is proven that the model for Li-ion batteries is superior, as the Lead-Acid battery must be replaced approximately 4 times more during the lifetime of a Li-ion battery. Additional data is included on the advantages of HHDVs compared to conventional diesel HDVs.