This past June 7th, what started out as simple commentary on the dyslexic’s delight (or would that be nightmare?) that a Toyota S-FR trademark could turn out to be mushroomed into a trivia buff’s revelations of a number of dead or abandoned Toyota trademarks and the heretofore unpublished discovery of a new Prius Prime trademark registered in late March of this year (which, in hindsight, probably merited its own separate story). So what, exactly, would a Prius Prime be? As we noted,
A number of possibilities come to mind for that badge: A fifth member of the “Prius family”? A top-of-the-line trim level for the 4th-generation Prius reportedly due in autumn of this year? A new denominator for the next-gen Prius Plug-In, possibly featuring a new wireless or inductive charging system? Or might Toyota decide to, for a limited time, offer the 3rd and 4th-gen Prius side-by-side in new car showrooms and give one of them the Prime denominator?
We failed to mention what is perhaps the likeliest use of that Prius Prime badge. Nearly a week before our article appeared, John Voelcker of Green Car Reports, in a commentary piece on a 4th-gen Prius test mule sighting in Thailand noted that
The new Prius is expected to continue with a nickel-metal-hydride battery pack in the base model, with an optional lithium-ion battery in a more expensive model that may offer better fuel economy.
And, upon our trademark discovery finally making its way to the PriusChat forums, member Inferno suggested that
Maybe the Li-Ion version instead of NiMH (with AWD). Because think about it, you’ll probably have your regular Prius trims of I II III IV and V
How confusing would it be if the LION version had just 4 more levels. Instead they could say buy the Prius Prime I, II, III, IV, and V with sunroof.
I’m still waiting for my Prius Prime minivan…
Actually, rumors of a lithium-ion battery option for the Prius go back further than that. Automotive News‘ late July 2014 Toyota predictions through the rest of the decade clearly suggest that Prius
…will get a choice of a low-cost nickel-metal hydride battery as well as a lithium ion version for different usage cycles.
And, in late January 2014, Automotive News‘ Asia editor Hans Greimel cited Hideki Iba, general manager of Toyota’s battery research division, as stating that
…engineers want to equip the car (4th-gen Prius) with lightweight lithium ion batteries, as opposed to the heavier nickel-metal hydride batteries the Prius has had since its 1997 debut. We aim to use lithium ion for Prius, but we are not sure yet. Or we could differentiate within the Prius lineup between ones that use lithium ion battery and other ones that use nickel-metal hydride batteries. The higher cost of lithium ion batteries is the main concern. Toyota is satisfied both with their power and energy performance as well as their safety. Lithium ion batteries’ safety and performance have been proved in the Japan-market Prius V wagon, which uses lithium power packs in a version that offers three rows of seats.
Ahh, yes, the 3-row Prius v. Most if not all markets outside North America that offer the so-called “big Prius” do so with a third-row “+2” seat facilitated by the use of more compact lithium-ion batteries, since the nickel-metal hydride batteries used in all of Toyota and Lexus non-Plug-In hybrids are too bulky to allow the fitment of the extra seating row. As PriusChat forums, member Inferno touched upon above, lithium-ion batteries could be offered in conjunction with an oft-rumored all-wheel-drive option for the 4th-gen Prius for similar packaging reasons. Then again, we’ll note that the admittedly taller and larger AWD versions of the Toyota Highlander, Lexus NX and RX hybrids all stick with nickel-metal hydride batteries, as does the AWD-only LS hybrid.
And bear in mind that reports of Toyota’s attitudes towards lithium-ion batteries are just as subject to wild “yes-they-will, no-they-won’t” gyrations as are the rumors of a reborn Supra, additional Toyota GT86/Scion F-RS derivatives and a separate sub-GT86 coupe. For every story like those cited above supporting increased use of Li-Ion batteries by Toyota, you’ll find other reports suggesting the carmaker’s ambivalence towards them and plans to bypass them entirely in favor of all-solid-state lithium-ion (expect them no sooner than the early 2020s), lithium-air (towards the 2030s decade) and/or manganese-ion batteries.