Would lithium make the Toyota Prius 4 much better?
Or is a split battery approach the best option for the fourth generation Prius?
When Toyota launched the third generation Toyota Prius without lithium, there was some disappointment. Likewise, when Toyota announced that the 2012 Toyota Camry hybrid would also continue to use NiMH batteries, there was further disappointment.
However, I’ve never agreed with this NiMH-based disappointment, and while I think the fourth generation Toyota Prius 4 will offer lithium, I believe NiHM could still play an important role in Toyota’s hybrids for some time.
In my opinion, if lithium was obviously so much better than NiMH for hybrid cars, then the lithium-powered Hyundai Sonata hybrid, for example, would offer better pricing and fuel economy advantages compared to the Camry hybrid. But it doesn’t. In fact, the new Camry hybrid offers a far more cost-effective package, especially based on some real world tests that found Sonata hybrid fuel economy missed its EPA-rating by as much as 10 mpgs.
Nevertheless, lithium is going to replace NiMH in most hybrid cars, eventually, and Toyota is slowly making this transition. For instance, in Europe and Japan Toyota is already switching to lithium in the Prius V. Likewise, the Prius plug-in hybrid will also rely on lithium. Consequently, once Toyota stabilizes its lithium supply chains, it only makes sense to quickly convert the fourth generation Prius 4 into a lithium hybrid. It’s simply the best path to a scalable battery advantage.
But that doesn’t mean that Toyota should completely kill off NiMH.
For instance, why not keep NiMH in the smaller and cheaper Prius C in the short term? Such a move could probably help keep costs down by enabling Toyota to take full advantage of its NiMH investments. Likewise, perhaps Toyota could continue to build the NiMH-based third generation Prius as the cheaper base model of the conventional Toyota Prius — something Toyota considered doing with the 2nd gen Prius when the 3rd gen Prius was heading for launch.
Unlike any other automaker, Toyota has a very significant NiMH advantage, and if they can use that advantage to build the most cost-effective hybrids, they should. Ultimately, moving hybrid technology further into the mainstream — a key long term goal of Toyota — isn’t dependent upon the name of the battery technology used, but the price.