[In reference to http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Ford-And-Tesla-Pushing-Toyota-To-Adopt-Li-ion-tp4664317.html EVLN: Ford And Tesla Pushing Toyota To Adopt Li-ion ]
I pawed through the evdl nabble archive on this and found that ... Toyota had preferred to use NiMH for their hybrids for quite some time ... http://www.evdl.org/archive/index.html#nabble-td3085326 Toyota will stay with NiMH for 10+ years, Chevron-out/ECD-in + Dec 13, 2010 The following newswire explains that TMC improved on the NiMH design (along with some other money saving techniques) ... http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Building-hybrids-on-the-cheap-td4658568.html EVLN: Building hybrids on the cheap Oct 12, 2012 ... Toyota Motor Corporation, instead of switching to Lithium-ion [Li-ion] battery packs, which are more expensive, was able to make its current Nickel-Metal Hydride [NiMH] battery packs more efficient. They did this by changing the shape of individual cells from cylindrical to flat, and modified the case to improve cooling and lifespan. Toyota also switched from 500 V to 650 V, a decision that produced “a host of benefits,” says Justin Ward, advanced power-train program manager at the Toyota Technical Center. Toyota was able to reduce the size of the drive motor without sacrificing performance. This small change reduced the amount of copper needed in the motor assembly, and therefore the cost of the component ... Ford had switched to using Li-ion in their hybrids a while ago http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Ford-s-New-Hybrid-Battery-Pack-Testing-Techniques-td4660294.html EVLN: Ford's New Hybrid Battery Pack Testing Techniques Jan 01, 2013 ... Unlike previous-generation vehicles from Ford’s lineup that featured nickel-metal-hydride (NiMH) batteries, li-ion batteries offer numerous benefits – including a size 25 to 30 percent smaller, and the ability to provide about three times the amount of power per cell than the previous state-of-the-art NiMH battery technology ... With all this chatter about NiMH, it had me thinking, that maybe, just maybe NiMH would begin to be available the public (unlike before). We all know about the NiMH patent lockup so no one could get them: http://www.winonarenewableenergy.com/1/post/2012/04/ev-batteries-are-being-held-hostage.html http://en.wikipedia.org/wiki/Patent_encumbrance_of_large_automotive_NiMH_batteries http://en.wikipedia.org/wiki/Cobasys#Criticisms But the patent and manufacture of large format NiMH batteries has changed hands. Yet, a search really only shows individual cells yanked from hybrid vehicle packs for resale. http://www.google.com/search?hl=en&tbm=shop&q=nimh+batteries+prius -Where can a person buy large format NiMH cells to build a pack for their conversion? Some in the media may say it was the high energy density of Li-ion that got us where we are today. But it is more likely that the 'availability' of li-ion that really tells the story. So, I was wondering, what if NiMH 'had-been available' a decade ago and the CARB mandate had as much teeth (support) as it has today? {Dream mode on: let's assume NiMH large format cells/pack were available 10+years ago} So, if today's production EVs were using a NiMH pack of the same Ah density ... -The range would be the same, right? Or would a NiMH pack weigh more? -What would be the cost difference? Does the older NiMH technology cost less to manufacture? Perhaps now that li-ion is the standard, NiMH price will drop? If NiMH had not had the blockage to keep it from being available, (and political forces had allowed CARB to do their job), we could have had compliance EVs over ten years ago in the 2000's, right? Back then automakers would have to use their (older) ice sedan platforms for their compliance-car: http://en.wikipedia.org/wiki/Ford_Escort_%28North_America%29#Third_generation_.281997.E2.80.932002.29 Ford Escort http://en.wikipedia.org/wiki/Chevrolet_Malibu#Fifth_generation_.281997.E2.80.932003.29 Chevy Malibu http://en.wikipedia.org/wiki/Honda_Civic#Seventh_generation_.282000.E2.80.932005.29_-_EM2.2C_ES1.2C_EP1.2C_EP2.2C_EP3.2C_EU1.2C_EV1 Honda Civic In those days, there wasn't any L3 EVSE standard. But what if one had been implemented? -What is the %SOC point one wants to stop charging NiMH at high current levels? Is it 80% like with Li-ion? -Does the pack heat up more or less than li-ion and require cooling? Corrections & comments are welcome. {brucedp.150m.com} -- http://www.fastmail.fm - Or how I learned to stop worrying and love email again _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
