odds on replacing NiMH with Li-ion?

I think it would require all new battery charging circuitry: new inverter, new CPU software, and new Battery, or even more likely, new car.

My feeble understanding is, Nickel Metal Hydride and Lithium Ion have totally different charging strategies.

http://en.wikipedia.org/wiki/Nickel_metal_hydride_battery#.CE.94V_charging_method
http://en.wikipedia.org/wiki/Lithium_ion_battery#Charging_procedure

 

Toyota is in the business of selling cars, not modifications to cars. They do have their TRD parts, but I suspect this is a way of promoting more sales of Toyota cars. I don't see their motivation to sell "improved*" battery technology.



*NiMH is an already proven tech for hybrids. Li-Ion hasn't been proven in mass quantity for automotive applications yet.

 

I didn't vote, since the options force a conclusion. My opinion is that the new batteries will not be backward compatible with the current Prius. It will also not be enough of an improvement to compel me to trade in my Gen II.

Tom

 

I would only upgrade to Li if the car was also a plug-in. And I would trade for a new car, not convert current car.

 

Ditto.

 

Can't vote, my option isn't there.

No, and I'm keeping my car, I love it, it's fantastic, who needs the latest and greatest all the time, next year it will be out of date anyway.

Where is that option?

 

To use LiON batteries, the vehicle control laws would have to change. In particular, the rate of charging can not exceed the battery capacity to accept a charge and that is one of the significant challenges of LiON. In contrast, the NiMH batteries appear to be more robust in this area.

The second problem has to do with environment, the temperature. The NiMH battery seems to have a wider operating range than LiON and especially in the high temperature range. GM addresses the problem in the Volt with an active, environmental control system, heaters and coolers, to keep their LiON batteries 'in a happy place.' But that does not come free. When the car is parked, the active environmental system has to run to protect their LiON batteries.

I have great admiration for the pioneers who have taken on the LiON challenge. But I don't see it as being free of severe engineering challenges.

Bob Wilson

 

I have not voted .... I cannot understand the interest in the Li-ion battery. I find the G3's electrical system completely satisfactory. There has never been a low voltage issue; the ICE is not over-worked; teh fuel efficiency is acceptable and etc.

I presume the change would require a major re-work of theelectrical and computer system.

I also assume those interested in the Li-ion battery are more interested in the EV mode that I am. My driving habits are not in sync with an electric vehicle .... that is why I bought the Prius.

 

Toyota's battery guru spokes persons have already flat out stated that they've done TONS of research on BOTH chemestries. From that research, they have also stated that they have NO intension on switching chemestries. They're happy with NiMH. It is possible that from that research they've determined something they don't feel like sharing with the public ... whether it's availabilty of the metals, longevity, or what ever.

 

Ther's no option in your poll to simply say No

 

This^^^

No one. Not a single maker has been able to give any estimation or statement about the longevity and durability of the Li-Ions. In fact just the opposite is true. Nearly all of them, including Toyota, have indicated that the Li-Ions are not expected to last as long as the NiMHs. At some time during the first 3-7 years the batteries will have to be replaced....at this time.

This puts the Li-Ions at a severe commercial disadvantage vis-a-vis the NiMHs which are effectly lasting for the life of the vehicle with no replacement.

Much much more has to be discovered, developed and tested. Maybe by the middle or end of the next decade?

 

Differing charging technologies aside. If I replace the Ni-MH batteries with Li-Ion technology; it will only give me about 40-50% more energy density. So I can coast for 0.75 miles instead of just 0.5 miles on EV. It won't change the fact that the primary source of power for the Prius is still gas. The battery is only used for recovering and reusing energies that would have otherwise been lost to inefficient ICE usage and braking. I dont see it being worth the bother (IMHO to switch/upgrade during a model year. Heck, it isn't even 2010 yet! and i'm just tickled enuf at the moment, that i've gone from 17mpg to 51mpg. For me that's a savings of around $900 in gas a year! hehehe

rich

 

Totally agree, the Li-Ion battery has a shorter life than the NiMH battery.

I have some Li-Ion and NiMH laptop batteries which were in storage for the last 8 years, I fired them up recently by recharging them. Only the NiMH will recharge to full capacity while the Li-Ion will not take any charge and all dead. It means the Li-ion has shorter shelve life and usable life.

 

Li-ion is supposed to be much better than NiMH. Lithium Ion has a life span of at least 10 years. The batteries are much lighter and are enviromentally safe; and there is supposed to be more power available from them too. NiMH Supposedly can't be recycled and require more precautions for EMS if there is an accident. The big problem I heard about Li-ion is the cost of the batteries. As more auto manufacturers use the new batteries the prices should drop.
The auto manufacturers are so excited about the new technology, GM is buiding a battery plant using Li-ion as their battery of choice. Read about the A123 type batteries on the web. A123Systems :: Home.

 

Don't forget potential heat build-up problems.

 

The A123 web says the "PROJECTED" life is 10 years without guarantee. The way they calculated the life is base on their testing that the battery had lasted 200K miles, for a normal user at 20K miles a year, then the battery will last for 10 year. Unfortunately batteries do not work that way.

If the battery will last 10 years as they said, why will they only give 3 years warranty only?

 

What the heck are you talking about? There is so much 'wrong' here it's shocking in this day and age.

 

And we put stock in what GM is doing? (Opposed to losing all our stock in GM). What's good for the General is not necessarily what's good for America any more.

I'll wait until Toyota brings out the new technology or wait until GM screws it up a few times to work out the bugs.