Ideal would be outlasting the engine and transaxle. I suspect the battery longevity depends very much on conditions plus time...not to mention luck of the draw. If the HV battery experiences high amp draws, extreme temps, and/or high/low levels of charge regularly then it would be unlikely to last as long as one that rarely did much more than provide a little push and regen.

I've seen a thread or two about folks in specific situations where the battery seemed to suffer premature failure (daily extreme charge/discharge in the mountains for example.) If one was doing full throttle acceleration to interstate speeds regularly then hard braking I would expect the high amp discharge/regen as well as the range of depletion/charge to be an order of magnitude more detrimental to the battery than a typical commute or highway drive.

I see a few GenII Prius yellowcab taxis locally on the highway from time to time. Haven't had the opportunity to speak with the operators yet.

I can't wait to hear from Toyota that the Li ion pack will last 10 years and 150K miles.

According to the article last week Toyota can't promise anything near that longevity right now. They like Nissan and GM are expecting that the Li-Ions will have to be replaced at sometime during a vehicle's expected life.

that would happen with every battery type on the market today
litium basis is not the battery type of the future but one of today.
and you will always have to replace a battery at some point.

there are other battery type's being develeped that have far greater capacity then litium ion typ's but do not expect them on the market the next 10 years.
i am talking about litium( and other chemistry)-air battery
+1000Wh/Kg energy

Art Spinella ... get your fingers out of your ears



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The warranty for the 2001 Prius was 10 Years or 100,000 miles, which ever comes first. My 2001 Prius battery failed in Jan 2009 at 192,000 miles. My sister-in-law has an identical car and its battery failed in Sep 2009 at 127,000 miles. I think that time is more of a limit on the life of a battery than miles.

The replacement battery in my car has failed with the odometer now reading 218,000 miles. The battery has lasted only 8 months and 26,000 miles. The battery came through a Toyota dealer and it took almost six weeks for it to arrive.

Does anyone know if there is a way to determine the date of manufacture of a hybrid battery?

I am thinking that the replacement battery was shipped from a warehouse in Japan where it had been setting for many years and is probably as old as my Prius. Toyota and I are having a debate about the premature failure. The word that I have from Toyota's Customer Experience Center is, "Toyota has no program that covers products that are outside their warranty period." I have sent a message to the North American Office of Toyota Motors and at this time have not received a response.

Actually the Classic traction battery warranty was 8 years/100K miles.

I assume that you paid for the replacement traction battery. Is that a good assumption?

If so, that battery should be covered by a one year/unlimited miles warranty. Do you find that this is not the case?

I would expect that the traction battery modules have a date code, but this may not be decipherable.

unfortunately, unless there have been some big advances, I do not think the Li batts will be anywhere as durable and long-lasting as the Nimh packs are.

It will be hard to beat NiMH in cost and reliability. Toyota has it locked up and it will be the key ingredient for a rock solid reliable hybrid.

I purchased an extended warranty that raised the time period to 10 years.

At 192,000 miles my Prius was way beyond the warranty period so, yes I paid for the replacement battery, $1959.50 plus removal and install charged from ny mechanic for a total of $2300 +.

The replacement battery was installed 26,000 miles and 18 months ago (January 2009) so it is not covered by a warranty. I am hoping that Toyota will make me a deal because the battery died so early.

My mechanic says that he did not find any numbers on the battery that could be an identification number.

I am expecting to buy a rebuilt battery from David Taylor at Re-Involt at Sanford, NC. He replaces the cells in a 2001-2003 Prius Battery with new cells for a 2008 or 2009 Prius. His price is $1475 plus about $200 shipping.

Toyota may not have a warranty on the replacement, but that is not acceptable for a battery that is only 26,000 miles old to fail, especially in light of the fact that it cost you $2300 to replace the original.

Owch!

I suspect the battery self-discharged in storage. What I'm finding is once the modules self-discharge low enough, there is an 'activation' charge cycle that has to be followed to restore the original capacity. This was quite a surprise to me back in January when I started working on refurbishing the old style, NHW11 modules. FYI, I've not publicly shared this with but one other and I suspect he has seen similar behavior.

I tried an experimental charger that used half-wave, voltage limited rectified, small current charge but it apparently is not the 'activation' charge protocol mentioned in various obscure NiMH papers. Until this mystery, how to 'activate' NiMH batteries is solved, I am going to be a little skeptical of any previously manufactured, NHW11 traction batteries.

Seriously, there is a lot we do not know about NiMH chemistry but that is for another day. For example, I found one reference to self-discharged batteries losing one of the rare earths into the electrolyte solution. If this is the case, it may be irreversible and support the hypothesis of a time limit on the NiMH battery life. But again, this is another failure mode that needs analysis before we 'set our hair on fire and jump off the roof.'

One encouraging thing is my earlier NiMH refurbishment of NHW11 traction batteries restored original capacity after re-hydrating the modules. Understand there may be multiple, independent phenomena involved with different mechanisms and outcomes. So please, please, please, understand you're at the limits of my ignorance about NiMH batteries.

Bob Wilson

I've lost many a NiMH battery to just such self discharge. Sometimes I can jolt them back to life, but often a formally good battery is rendered unusable from sitting in the battery drawer.

Tom

A Prius 150K warranty could be a death blow to the Volt. They've already failed/refused to warrant the Volt's Lithium pack ... refusing to apply for AT-PVEV status:

http://priuschat.com/forums/chevrol...t-bad-news-couched-good-news.html#post1153554

(which means you WON'T get a $5,000 credit in California if you buy it ... THAT will make for a really heafty price).

Hasn't the patent run out on the original large format Panasonic NiMH battery used in the RAV-4ev/EV1 ?? With NiMH proving to have such a long life, I wonder why it's not being re-vamped?

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Sorry, I don't want to step in an be unpopular...not like I haven't done that before. But IMO despite the fact that Prius Faithful love seeing, hearing and reading headlines and articles like the OP's linked article, IMO the article is very poorly presented.

First of all the headline screams "Prius Battery Pack WILL last 10 Years" then the article immediately contradicts changing "will" to "could". Big Difference.

I've researched enough, that I know the apparent reliability of the NimH battery packs. Nothing as presented is disingenious, but most people have a 6-8 year warranty, and regardless of what a "independent" study initiated by Toyota Motor Corporation finds, I'd still caution most typical owners against expecting 400,000 miles of service.

Given all the unfair negative publicity that Toyota has received the past year, a little positive propaganda is probably warranted. But given that the headline is misleading and the warranty for most people misrepresented, I still have to say it's a poor piece.

It's all changing rapidly anyway. The next decade is going to be evaluating the long term reliability of Lithium Ion Batteries...while not vanishing tomorrow, I do not think the future is NimH despite the reliabilty that has been demonstrated.

Good question and this time, Wiki isn't very helpful: [ame="http://en.wikipedia.org/wiki/Patent_encumbrance_of_large_automotive_NiMH_batteries"]Wiki isn't very helpful[/ame]
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I thought it was 2014 but I'm not an expert in this field. I've also seen Google claims of 2015. Regardless, I hope to be around for the 'patent burning' (like a mortgage burning.)

One interesting URL: http://www.energyconversiondevices.com/patents.php

Bob Wilson

Are you saying that Toyota claims the replacement battery is out of warranty because it wasn't installed by a dealer? What is the warranty for parts sold over the counter but not dealer installed?

.I have a 2005 Prius with 135,000 miles. I was told by the dealer today that battery is dying and needs to be replaced. $3600.00 is the price that the quoted.
They charged me $95 for the test.

Yesterday I was an avid Prius fan, today I'm not so sure.