2001 Prius Battery

Rick, you may wish to review the most excellent thread http://priuschat.com/forums/generation-1-prius-discussion/84017-nhw11-traction-battery-autopsy.html

ReInvolt sells known good Gen I NiMH modules for $10 + shipping on ebay. You'll have to pull the traction battery anyway, might as well see if it is something as simple as replacing a bad module or two with good ones. I'm following this route with a Honda traction battery as I type. I'm not knocking the ReInvolt product, the Gen I battery replacement filled with Gen II modules, but you might be able to save quite a bit of money provided it is something simple. Absolutely it is not worth it to pay a dealer for a replacement Gen I battery.

 

You've nailed it. Feel free to enjoy my battery testing results:
Prius Battery Photos

One thing about P3009, it can be an intermittent problem. You might consider pulling the ground on the 12 V battery for ~5 minutes which clears all codes. Then reconnect and see if it comes back. There are no guarantees but it is a relatively low-cost solution.

GOOD LUCK!
Bob Wilson

 

That's an important point. Some vendors, unfortunately, advertise such batteries as "remanufactured". They are not. They are simply used batteries adapted to a different case.

Gen I modules are sized so that all sides are adequately cooled, and so that there is a safety margin of crush space in the event of a collision. However, Gen II modules are longer and don't properly fit in the Gen I case. You have to push the case down hard over the modules to make the case fit together, and it is an interference fit. That's not the way the battery was designed.

This presents a potential problem. All cells age, and cells from two different battery packs will have aged at different rates. Mixing such cells increases the possibility of failure.

So-called "proprietary" processes cannot reverse the aging process. However, you may be able to get lucky and find two packs that get along. It takes time to find out.

A variety of shops and individuals have been stuffing Gen II cells into Gen I pack housings for the past couple of years. However, they have no way of knowing how long the packs will last, because not enough time has elapsed to tell. Nor have any, to my knowledge, addressed the issues outlined above.

It's possible that such battery packs may be a good deal for folks who plan on driving the car for no more than a year or two before unloading it on someone else. But for someone who wants their battery investment to last, it's simply too soon to tell. Not many folks want to hear that.

 

I my experience, coincidences after collision/collision repair usually are not coincidences.

I would do two things before shelling out for another battery.

1) Get the actual voltage and internal resistance values from the battery. Your Prius tech should have captured them when the scan was done. (assuming Techstream was used). While this is not comprehensive, it will give you a pretty good inclination as to the batteries health.

2) Make sure you don't have damage to the orange wires/connectors on the inverter. That is on the left front, right where you indicate the collision and repair occured. I have seen cracked inverter cases from front left collisions. I've seen P3009 manifest intermittently due to water intrusion. The right way to test this is with an insulation tester/meg-ohm meter. A visual inspection would be a good place to start.

Most body shops don't know anything about this stuff.

P3009 indicates HV current leakage, not necessarily a bad battery pack.

According to TIS, the following are potential trouble spots that can trigger this code:

 Power cable
 HV transaxle
 Converter & inverter assembly
 Battery cover
 System main relay
 Battery temperature sensor
 Battery ECU
 Battery carrier catch bracket
 Main battery cable
 Service plug assembly
 HV battery assembly

TIS has a 10 page procedure to go through this diagnosis. Demand that the Prius Tech find it, print it and complete it.

If you don't complete the diagnosis, you may spend a bunch of money on a battery and not solve the problem.

I'd stick to my guns and make the insurance company get the car running!

PM me if I can be of any assistance.

Eric

 

rensor1:

I had a p3009 in my 2001 back in late August which recurred several times and then went away. I continued driving the car while monitoring module blocks using a scangauge II, and although I never saw any more evidence of a voltage leak, it was pretty obvious that my battery had seen better days.

I have been working with two batteries, trying to salvage the best modules from each to make a single working battery. My progress has been documented in these threads:http://priuschat.com/forums/generat...85773-p3009-battery-frankenstein-project.html and http://priuschat.com/forums/generation-1-prius-discussion/84017-nhw11-traction-battery-autopsy.html

Notice the photo in the initial post to the Frankenstein project thread: The lump of electrolyte on top of module 18 is clear evidence that the battery was leaking. But apparently the water dried out of it, and the resistance went up, eliminating the voltage leak that the ECU was reporting.

Twice, when the P3009 appeared, the weather was super hot, and the car had been sitting in the sun. When the car turned on the battery fan also went on full blast.

I have no comment on whether the crash may have been related to the cause of the code, but did you notice at any time that the car was particularly hot? Or that the fan was running abnormally fast?

 

They are not claiming to reverse the aging process, only to balance the modules, precisely so that they do "get along." As to the aging process, by using gen II modules at least they are assuring that they are using modules that are newer than any used gen I modules. Given that I've done a lot of work characterizing the modules from the two gen I battery packs I have, I can say that I have a pretty good understanding of what it means to match the charge characteristics of the modules in a particular pack, so I can speak to that. We'll see how my project works out.

Re-involt has more experience than I, with a significant installed base of their product. And from what I hear they stand behind their product better than Toyota does. All for less money. I don't really see a problem with that.

 

No, it won't. If a vehicle comes in with a P3009, the tech is likely to scan the vehicle in their bay. Such data will give very little indication of battery health, as the battery has almost no load.

You can read more about this in the diagnostic section of Toyota's service manual.

 

I didn't see anyone say that the vendor had claimed to reverse the aging process. Rather, it was pointed out that they cannot do so. It's not hard to find enough decent used modules to make a pack to last a year or so. However, no one yet knows if the packs will last much longer than a couple of years.

Actually, they offer the same warranty.

 

Oldnoah, I certainly wish re-involt well also. However I would not yet be prepared to say that they "stand behind" better than Toyota.

In addition to Toyota's defined warranty coverage on NHW11 traction batteries, there was a no-cost special service campaign to check for and re-seal leaking modules. Some number of battery asemblies were replaced for free under that (T knows how many...). Admittedly, we could suggest that this was cleaning up after a design or manufacturing defect, but there it is.

In addition there were some number of free, post-warranty replacements of battery asemblies. Some of these were offered outright, and others required a bit of 'discussion' with the Toyota Customer experience center. Once again the numbers are proprietary for Toyota, but more than a few cases have been chronicled over time here and at the Yahoo groups. In addition, some transaxles were replaced for free out of warranty. Maybe some power steering asemblies? I don't know of this happening for the accelerator pedal assemblies, hence the ocassional $500 to $700 sadness we have read about.

We may now be past this period of Toyota's largesse, but I don't judge their support solely on terms of the warranties.

Meanwhile, based on the cooling air circulation issue raised by jk450, I certainly hope that Re-involt (or some of their customers) are taking a close look at temperatures in the rebuilt packs, under heavy loads. That would seem to me the best way to know if this solution will be successful in the long term

 

An interesting hypothesis, where is the test data? Air flow measurements? Temperature measurements?

Now I've compared the two module styles:

I don't see a significant obstruction of the air spaces above and below the battery. The end sides are a small fraction of the surface area compared to the volume. We can do the math but perhaps the advocate of the theory should show their work. <grins>

This image shows the older module laying on top of the NHW20 module outline:
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The only significant changes are the ends, the minor exposed surfaces.

I prefer to treat a hypothesis as just that until it is followed by empirical data. To which I would add:

.
SAE 2004-01-0064 "Development of New-Generation Hybrid System THS II - Drastic Improvement of Power Performance and Fuel Economy" Koichiro Muta, Makoto Yamazaki and Junji Tokieda.

The lower internal resistance reduces heating from (I**2)*R losses and improves vehicle efficiency. This means less cooling is needed. Perhaps the advocate of the 'cooling' hypothesis might bring measured internal resistance of the NHW11 and NHW20 modules and show the relative heat loads.

Now Daryl who I helped to swap his battery:
.

We just went through one of the warmest summers in recorded history and his car with NHW20 modules is working great. He has not reported a problem with his battery which is what I would expect. One happy customer is not enough but I notice Re-InVolt still has a one year warranty and to the best of my knowledge, stands by his product. He is still in business.

Bob Wilson

 

Forgive me, "stand behind" is not a quantifiable term, and I said it without much consideration. My offhand remark was part of an admittedly knee-jerk response to jk450's composition fallacy.

 

You raise a good point, tochatihu, and I know of some folks who have had adjustments made as late as a few months ago. At this point, they are usually getting a break on parts and/or labor rather than outright free repair. Will the aftermarket folks do so, as well, as much as a full ten years after some of the batteries were sold? They are not obligated to do so, of course, but the point is well taken.

Yes to both.

Nor do I. It's important to look at the big picture.

Given that the packs only have a few temperature sensors, and that those sensors are not mounted in the outermost cells of each module, I think one would have to develop a custom sensor array to do the job properly. Proper data collection takes care and attention to detail.

I think it would be hard for a small company to do that. They would have to develop a stable database of known good battery packs, and run them long enough after testing to verify that they would also have to duplicate the load testing precisely. They would then have to test a large amount of battery packs constructed out of used Gen II modules. And even if they found higher temperatures in battery packs that failed early, they would have to at least entertain the notion that one may not be the cause of the other.

Please note that I'm not suggesting that any company that sells Gen I battery packs made out of used Gen II cells actually carry out such research. It would take too long and cost too much money for the average mom-and-pop establishment to do so. However, in the absence of such information, it is obligatory that such businesses offer an honest assessment of their own products, if asked.

Folks who buy Gen I battery packs made out of used Gen II cells are likely to hope and expect that the battery packs last well beyond a one-year warranty. But no vendor yet knows how long these packs will last, on average. We hope for the best, of course, but the paying consumer deserves to know this. It is interesting to see folks in this forum opposed to that.

As for Re-InVolt in particular, the proprietor has made several strong claims while promoting his products on this forum. Here are two:

1. Toyota's replacement battery packs are in no way improved over the original packs that were subject to the Special Service Campaign.

2. Re-InVolt can establish battery pack date of production by looking at module serial numbers, and has found so far that replacement battery packs have been manufactured in 2008 or earlier, at the latest.

If substantiated, these claims would obviously help cast Toyota's products in a poor light, and by comparison, elevate Re-InVolt's reputation. However, the proprietor of Re-InVolt has been asked to provide the reasons for making such claims, and as of this writing, has not done so. This, of course, does not establish whether or not such claims have any truth to them. But until such claims are backed up with fact, folks can be forgiven for exhibiting a bit of healthy skepticism.

 

Actually, it's not a hypothesis, but a question. The cooling system is compromised; you can easily see for yourself if you look at an actual pack. Does that affect battery life? That's the question. However, if you're looking for data, you would do best to ask the folks who have assembled such packs.

Not to state the obvious, but that's because you have displayed a photo of battery modules surrounded by air, rather than the case itself. There is no obstruction because there is no case.

It was pretty simple, really. No math was required. When I inspected a ReInVolt battery pack that had failed soon after installation, I noticed that it took a lot of effort to remove the top case, which normally lifts right off. Upon further investigation, the new modules fit so tight that the case had to be pushed on with a lot of force to get the bolts close enough to where I could even start the threads; there was still about three-quarters of an inch gap between top and bottom case.

This means that after pushing down with all of his or her might until the case would go no further, because of interference with the modules themselves, the person who assembled the pack then had to use the bolts to pull the case down the remaining three-quarters of an inch. What was the clearance after the case was forced down even further?

To eliminate any other factors that might affect my observations, I tried to install the upper half of a Gen I case on top of a different Gen I lower case that had 38 Gen II modules installed. Same results. So you see, you don't have to take anyone's word for it. This is an experiment that you can do yourself.

Let me stop you right there. As mentioned above, there is no hypothesis, but a question: does the compromised cooling system affect battery life? That's a fair question, and it is reasonable to expect anyone selling such products to respond to it. Let's give then a chance, shall we?

Let's back up. Someone replaced a battery pack with one built out of used Gen II modules. The battery has a one-year warranty, has lasted about seven months as of this writing, including through a very hot summer, and the person who sold the battery is still in business. While I hope that the battery lasts a long time, the above statements don't establish much of anything about the battery pack, in the long run.

One would think this would be an obvious point, but since it's apparently not, consider this:

Some time back, a person posted to this forum that they had purchased a replacement battery pack from Toyota that had failed not long after its warranty expired. But by your standards, that battery would be top-notch, right? After all, it lasted more than seven months, it had a 12 month/12,000 mile warranty, and Toyota is still in business.

I remember that you were one of the first to post in this forum, recommending Re-InVolt's products. While I hope the battery packs work out, it was pointed out at the time that you didn't have nearly enough data to make a long-term assessment. That is still the case.

 

If you feel that I have posted something that is in error, please point it out.

I would be grateful for the correction. Inaccurate information helps no one.

 

While I was assembling my battery pack today, I couldn't help thinking about all this controversy, and wondering just what is the air flow path through the battery case.

In the first picture, you can see the black seal line that runs around the top of the modules, and across the top of the end plates. This appears to be a dead end path. Likewise, you can see the seal line that runs along the bottom of the modules, and then up the face of the end plates, which also appears to be a dead end path.

In the second and third photos, you can see that there is ample space on either end of the module, except that where the buss bar holders are in place, there is no space for air flow over the top half of the module, because it's obscured by the buss bar holders and covers. On the lower half, there is about 3/4 of an inch, which is way more than is necessary to accomodate the gen II modules. The interference jk450 is describing comes from where the top of the case is tapered, and since the gen II modules are slightly wider at this point, the buss bar holders get squished by the taper, but since the buss bars are already covering the top of the module, this has no effect on the air flow there. But wait, there isn't any air flow here to start with, because this part of the case is outside of the seal which directs the air into the space above and below the pack.

So just where does the air flow? The fourth picture is the reveal. And of course this makes sense, since it is the space between the modules where heat can be extracted.

 

This makes sense:
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You can not see the air inlet on the near side of the traction battery. The electronics are located slightly to the right and under the exhaust manifold. The traction battery draws cabin air in there so it cools the electronics and then passed into the bottom manifold under the modules. The fan then exhausts the heat which also rises. So after the car is parked, convection continues to cool the traction battery.

Thanks, great photos.

Bob Wilson

 

That is the primary air flow. It has been discussed in the forums as well as in technical papers. And yes, it is designed to carry heat away from some of the hotter areas of the modules. This is common knowledge.

Now think about secondary flow. Treat the battery pack as a system, and ask yourself why Toyota designed the case the way that they did.

 

You are right! Here is an illustration that shows the air flow path:



http://www.autoshop101.com/forms/Hybrid03.pdf

Air is flowing from bottom to top in between the modules (and maybe from the sides too?).

NREL has done infrared thermal imaging comparing between Gen 1 & 2 batteries:

http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/38164.pdf



Gen 2 batteries have lower and more uniform temperature distribution due to improved design of 2 welds point instead of 1.