Is there a way to find the date that a Prius Hybrid battery was manufactured?

If you are referring to the HV battery, a replacement unit is warrantied at 12 months/12,000 miles.

 

Then he is out of warranty...

Anyways, just forget OEM's, and buy the reinvolt battery. It will last longer and is cheaper.

As to your question on manufacturing date, I would assume there is a date code and batch code, but it is probably complete jibberish unless you know how to decode it.

 

That is correct.

ReInvolt battery packs are unproven. Furthermore, their design compromises the cooling that Toyota builds into all of their packs. In addition, ReInvolt packs have in the past shipped with defects, suggesting that the rebuilding technology has not yet been refined.

Such defects are no doubt covered by warranty, but a pack would be a pain to return.

 

I'm having trouble understanding how a battery which is built from used 2G battery modules can be assumed to necessarily last longer than a new Classic battery. 2G model years range from 2004 to 2009. If the modules came from 2008-2009 crash vehicles, then I'd feel pretty good about the Re-inVolt battery. If the modules came from 2004-2005 vehicles, then who knows how much longer they will last.

There's no dispute that the purchase price is cheaper, which you should expect since the raw material comes from salvaged 2G vehicles.

My question is whether the Re-inVolt "remanufacturing" process adds sufficient value to make that battery worth the extra cost vs. buying your own 2G salvage batteries and DIY.

What aspect of the Re-inVolt design is responsible for diminished traction battery cooling?

 

One difference is I have 'hands on':

Folks are free to provide their backup data, like what I have:

• "Proven" - with Re-InVolt we have a proven supplier and satisfied customers.
• Where are your temperature measurements of the Re-InVolt pack showing a problem? Actually, where are any Toyota battery pack measurements?
• How many Re-InVolt packs had defects? Dates? Locations?
• Before February, every 2010 Prius was shipped with defective brake software but that does not means the 2010 Prius is trash. Just another defect that had to be fixed, part of an effective, quality control system.
• Warranty, the very thing the replacement Toyota pack has denied.
• Shipping is a well established technology.

Still, anyone could do what I did and call Re-InVolt and ask them:

Taylor Automotive
1007 Hawkins Ave.
Sanford, NC 27330
919-774-4037
​

I found they are doing what I've tested and found to work:
Prius Battery Photos

It is easy to post Fear Uncertainty and Doubt but a lot harder to address technical issues with facts and data. I'm ready to trot out my backup facts and data.

Bob Wilson

 

Perhaps you might conduct a study by getting samples and testing. For example:

• buy some NHW11 modules - I did
• buy a failed NHW11 traction battery - I did
• analyze the modules to find out what failed - I did
• use a smart battery charger to quantify module capacity - I did
• read the Dept of Energy literature on traction battery - I did
• read papers and books on NiMH battery technology - I did
• read the endurance test results on NHW11s - I did

Don't be like those who spouts FUD without first exercising some effort to understand the technology. I've been posting my battery experiments in PTS for years but it comes down to this:

1. NHW11 modules have weak terminal seals - Toyota tried the sealant fix but we have abundant evidence from corroded terminals and short to ground that it doesn't work all that well. In fact my test modules show strong base reaction in pH testing.
2. NHW11 modules lose the water in their electrolyte primarily by seepage out the weak terminal seals. Of the modules tested from the failed traction battery, all that had not failed hard responded and returned to original Ahr values by adding water. The Toyota patent on refurbishing used a KOH but my testing shows only water is needed:
3. NHW20 modules were built with a stronger case and improved terminal sealing. This closes the primary failure mode of NHW11s, the loss of water from the electrolyte.
4. Early indications of a self-discharge or lack of cycling can permanently fail NiMH batteries - this is an early observation and will require a long term study (i.e., at least a year or more to get quantitative data.)

So like the challenge to FUD, have you studied or analyzed any batteries to diagnose the failure mechanism?

I have and though more recent is better in any technology . . . manufacturing improvements will always make the latest better . . . I would take the first NHW20 modules over the latest NHW11 any day of the week after a charge-discharge cycling measures their capacity. One reason I did my testing was to find out how to maximize NHW11 battery life by avoiding what stresses the battery. Regardless, the redesigned, NHW20 module is significantly improved over the last NHW11 module.

Do what I did, call and ask:
Taylor Automotive
1007 Hawkins Ave.
Sanford, NC 27330
919-774-4037

Of course it helps to understand the technology before calling. David Taylor does not suffer fools gladly.

Bob Wilson

 

If we postulate, as the OP does, that time is the enemy of HV batteries, then your question becomes "I'm having trouble understanding how a more recent battery which is built from used 2G battery modules can be assumed to necessarily last longer than a unused but older Classic battery." If indeed time is our enemy here, then the newer but used cells should indeed last longer than the older, unused cells.

Mind you, I personally have yet another theory, I think the reason the batteries in the taxis lasted as long as they did was BECAUSE they were used. A big city taxi is READY almost 24 hours a day, the computers are able to babysit the SOC constantly, keeping it as 'tuned up' as needed.

In contrast, my car sits off 16 hours a day, so the computers are unable to 'freshen up' the charge on my batteries at the slightest drop in efficiency.

Should my theory why the taxis ran so long be true, "used" is a good thing.

If the OP's theory that it is time that is the enemy, then "new" classic batteries should fail soon after install, they have been sitting since at least 2003. If my theory is true "used" 2004 batteries should better than 2004 batteries that have been shelved since 2004.

(If I was Bob Wilson I would have bought a 2004 used battery and a 2004 new battery and driven them both 200,000 miles so I could graph the differences, but it is obvious that I am lazier than Mr Wilson)

 

You are in good company.

There are bits of the NiMH puzzle I've not yet figured out:

• cell activation
• long term electrolyte composition

Cell activation is a charging protocol that after the battery is manufactured, allows it to take a charge and begin working as a battery. The literature mentions it but I've not found a good, quantitative definition.

My module rehydration experiments showed they had to go through a series of charge-discharge after the water was added. I thought at the time this might be cell activation and it may still be part of the puzzle. One Korean patent reported heating the battery to 70-80C reduced cell activation time and one of my tests showed that to be the case. However, the time is still measured in days and practical NiMH manufacture needs something faster.

There is literature that suggests the metal hydride can lose some of the rare earths by going into solution in the KOH. There is speculation (not mine) that it may be possible to look at the charge-discharge curves to quantify this effect. In theory, the electrode potentials over different charging profiles may give enough information to detect when rare earths have gone into solution. Once in solution, they do not return to the metal hydride and the battery should be recycled.

Bob Wilson

 

Hi Bob,

I respect the very extensive work that you've done in the past, to develop an understanding of why NHW11 traction batteries have failed.

I don't believe that we know whether or not the NHW11 batteries that are currently being shipped from Toyota spare parts inventory include engineering changes to reduce electrolyte leakage and improve battery life. Therefore it is unclear that it is reasonable to assert that the oldest NHW20 module that is six years old is necessarily better than modules installed in the NHW11 traction batteries currently stocked as spare parts inventory.

I've looked at the Re-inVolt website a few times, including today, and think it would benefit from an explanation of the remanufacturing process used, without revealing secrets deemed to be proprietary. That would reduce the need of the owner to "suffer" contacts from "fools" or other interested parties.

 

It is why experimentation is necessary. My experience indicates that traction battery storage requires more than just sitting on a shelf or a maintenance charge, something that Cadex also claims:
Do and don't battery table

You are course welcome to your opinion but I would ask for the facts and data. For example, I retested my refurbished traction batteries a year and a half later and found they exhibit symptoms of self-discharge to useless. Worse, the other modules from that same traction battery won't re-hydrate and return to 6.5 Ahr capacity. They exhibit a curious peak voltage in the 8.5-8.6 V range and excessive out-gassing.

I'm just working from direct observations of my test articles.

One of the things David and I discussed is a set of traction battery rebuilding instructions that is available on the net. David and I share similar concerns about this paper. But if David publishes his methods, an upscaled version of my similar work, he is giving a road map for his competition. But worse, a competition unconcerned about the quality of the result.

Over in PTS we've seen a wide range of experimental work and a few spectacular failures. But folks there understand the risks and deal with it. In contrast, when offering a service or product to the public, David is doing the right things and other than taking a 'busman's holiday,' I have confidence in his work.

I don't expect to be a customer of his but should my traction battery give up the ghost, I'll call him before rebuilding the pack on my own. The reason is he has a larger inventory of battery modules to survey and quantify. I could buy two, NHW20 packs but there would be no assurance of equal capacity between the individual modules of the packs. In contrast, David has a larger pool and can more closely match the modules. This is key to a successful battery rebuild.

Bob Wilson

 

Your point is well taken.

I'm not sure how much cheaper it is, in the end. Gen 1 pack prices have dropped, and some dealers are starting to compete with each other with further price cuts. In addition, there are no shipping charges when you buy a Gen 1 battery pack from Toyota.

Given that I have seen a failed ReInvolt battery pack out of the box, and given that there hasn't been time to collect significant data on the ReInvolt packs, I don't yet see the added value. Perhaps things will change in the future.

Toyota's battery packs are designed so that there is adequate cooling air space around the tops and terminal ends of the modules, as well as underneath the pack's internal floor. As well, this space serves as a crush zone; while the terminals are recessed within the bus bars and covered by an insulator, they are further protected by free space in case of a collision.

However, when a Gen 1 battery pack is built out of Gen II modules, there is no free space at the terminal ends. In fact, the pack cover is an interference fit, and has to be pushed down with some effort to cover the modules. In most cases, the fit is so tight that the pack will not bolt together without some difficulty. To put it mildly, this is not as Toyota intended.

I remember reading somewhere that the ReInvolt pack housings had been redesigned to address this issue; on the pack I saw, there was no such redesign.

 

With all due respect, posting a picture of a ReInVolt battery pack does not prove that they are more reliable than replacement Gen 1 battery packs.

To begin with, the above conduct in inexcusable. This is a technical forum; there is no reason to display such acute anger or to accuse folks of lying when there is no evidence of that.

Returning to your question, I would direct you to re-read my post, in which I stated that ReInVolt packs are unproven; i.e. there is insufficient data to establish as to whether or not they will last. In short, the lack of data is at the heart of the issue. So I am not sure why you are asking for data, unless you misread my post.

See above.

Setting aside the insults for the moments, I would ask: why do you think the ReInVolt packs are "proven"? If there is any point where data is appropriate, this would be the point. Keep in mind that to establish that, for example, ReInVolt packs last at least 50,000 miles, with a failure rate of, say, 1%, you'll need to have independent data on hundreds of packs that have lasted that long.

I realize that you cannot be expected to provide such data, and I'm not asking for it. However, it is important to understand how much data is needed to really show that something works, and works well.

I didn't need to take any measurements. The ReInvolt pack set battery codes soon after being put into service, and a look at the datastream showed that the pack was unbalanced. It was easy to see.

I have no idea, and have at no point claimed to know. However, seeing just one ReInVolt battery pack fail soon after installation indicates to me that the rebuilding process has not yet, as I originally asserted, been refined. I stand by that statement.

Thanks, but this is not a brake issue.

By the looks of the original post, the warranty has expired.

Why the sarcasm? Why the emotion? It's a simple technical issue. I don't see any evidence that the ReInVolt packs are, as you say, "proven." You are welcome to believe otherwise.

But it seems to me that you have created a hypothesis and are looking for data to support that. Science doesn't work that way. Perhaps there is someone in your circle of friends with an engineering background. It doesn't matter what kind of engineering. Ask them to walk you through the processes of data collection, verification, and validation. I think this might help connect some dots that may be missing in your understanding. It's worth a shot.

 

That's correct. Folks who say the ReInVolt battery packs are "better" are assuming that no improvements have been made to Gen 1 packs, but they have no way of knowing that.

There's another issue to consider, as well: rebuilding Gen 1 packs out of two Gen II packs requires combining modules out of two packs that have aged at different rates, and spent different amounts of time in service. That doesn't always go so well.

Add to this the uncertainty regarding the compromised cooling system, and it is clear that one would have to collect a lot of data to support 2k1toaster's assertion that ReInVolt packs "will last longer", or bwilson4web's assertion that ReInVolt packs are "proven". They may be great packs, but it is pointless to say so with certainty in the absence of data.

 

The "last longer" is not backed by imperical data obviously, sorry to anyone that took it as such. It is on a hunch by generic battery standards. Time is definately an enemy. As long as the salvaged packs come from vehicles that have been driven with some amount of normalcy within the past 6 months or so, they will more than likely be better conditioned to last longer than a pack that has been trickle charging for 7 years on a shelf in Japan. Also the use of genII packs over genI packs is an obvious improvement to quality, however a degredation in safety as pointed out. I doubt anything will happen, but maybe mountain pass stressing the pack before being rear ended by a semi truck could result in disaster. Although when hit by such force, I think the traction battery will be the least of your worries...

Curiously, has anyone with a spare 'dead' pack taken it to Toyota and asked for the deep recharge service? The one where they put caution tape around the vehicle, and recharge it from the wall to 40%? Not sure of the price or time, but it would seem that Toyota would know best...

 

The difference is I 'do the experiment' and . . . (stuff that need not be discussed in public any longer.)

For example, the poster in "Gen 1 HV BATTERY REBUILD WITH 2G CELLS" asked about the fuses in the engine compartment. I sent him a PM and later, posted in another forum photos:








It is . . . and absent moderator action, . . . (we'll try the 'ignore list'.)

Bob Wilson

 

jk450,

Give it a rest, man !!

For all of us at PC, please do us all a favor and take your issues with Bob Wilson off line and please stop your petty nitpicking in front of everyone.

PM or call him and get whatever he did to you off of your chest once and for all.

Enough is enough. Both of you have a lot of knowledge to bring to the rest of us that are not as knowledgeable. Your following Bob around and finding error in everything that he says and does totally distracts from a lot of useful information that the rest of us are trying to follow and learn.

Thanks,

Dwight

 

I'm sorry to hear this.

That matches my experience and an a few reports by others who had to leave their cars unused for several months. They would come back and the traction battery would fail then. This is not a hard and fast rule but it also matches my recent experience with my test batteries.

I have found each module has a unique serial number. But I've not found anyone who can decode it.

Could you provide more details about the failure:

• codes?
• has the battery been taken out and inspected?
• does your mechanic have something like Auto Enginuity?

Do you have any interest in trying to fix it yourself? A place to do the work, instrumentation and tools?

Thanks,
Bob Wilson

 

That may be true, but I don't think Toyota builds battery packs and then trickle charges them for seven years before selling them. They build to demand.

Perhaps the OP's concerns stems from tales of lead-acid batteries sitting on store shelves for long periods of time. Dealerships usually aren't fond of tying money up in inventory, and many won't stock a Gen I battery pack. I suppose the OP could inquire as to how long their battery pack sat in the dealership's inventory.

If you're comparing one new Gen II module to one new Gen I module, probably. It gets more complicated when you compare packs, especially a pack made from two used Gen II packs as compared to a new Gen I pack. If you search the archives, you'll find that many folks felt that they had a good handle on battery reconditioning, until they assembled their modules into a pack.

Toyota will not charge a battery pack that is out of the car.

 

It is fairly easy to swap the packs. Drive to the dealership in a good car, put in the bad pack, ask for recharge. Of course tell them in advance so they can fly on one of the chargers, but you get the point.

We do not know if Toyota builds them to order, or built a bunch and now "maintains" the rest of the stock. Setting up a run of an old product is just as costly if not more so than making surplus to begin with and hoping to never have to start that production line again.