Why do “hybrid” autos have expensive batteries?
It has to do with power density. The best known hybrid is actually the submarines prior to nuclear power, with massive lead-acid cells. Diesel-electric. Worked fine, lasted a long time and drained to the bilge. Run on the diesel on the surface and charge the battery, then run on the battery only when submerged. Nuclear submarines have a battery, with about 1/5th the capacity of a diesel electric which works just like the battery in your car, used for starting it up mostly, though it can be used in a pinch to drive the screw through an electric motor for a relatively short period of time as compared to the diesel electric.The main problem with lead-acid is physical size, and the electrolyte is a liquid, sulfuric acid, which in an auto accident, would be a significant hazard. The problem with a car is again, the physical size of the battery and how much power it holds. Current hybrids use NiMH for the most part. Lithium cells are just too expensive, though have a higher power density. Th
