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

As far as I know, it's not a service you can order. They need a reason to charge the pack.

The packs are often shipped to the US by air. I doubt Toyota would spring for air shipping of a product that's been laying around. Besides, most of their production is based on the just-in-time philosophy.

 

Honda overnight air mails everything, even standard parts sitting around. It is done based on the customer not wanting to wait. I needed a little trim piece for my civic. I went to the stealership, they said come back tomorrow. Came back the next day in the afternoon and my package was there overnight from Ontario, Canada. I wasnt charged for fast shipping (well other than the always high prices, but I would have paid the same price if it was in stock at my dealership in Colorado).

I just dont see a justifiable way for such a large coorporation to build one-offs. It makes me think there is almost just "some guy" who's sole job it is, is to hand build new genI packs. I am still thinking they must do limited runs and stockpile. Even if it is every 12 months, they make say 100 packs. Just doesnt make fiscal sense (or cents )

EDIT: If your car dies, and the dealership says "We need a new battery. They will make one for you in Japan. That will take 2-3 days to get the production line ready and the parts avaialble, assembled, and tested." I could live with that part. "Now, it is going to take 6 to 8 weeks on a barge before it gets to California's port of entry. Another day or two to get to us, then we can install it." That is idiotic. They airmail everything like this so your car isnt at a dealership for 2 months.

 

I doubt they're "made to order". They're not going to build and ship you a battery fresh from japan the instant you place an order. Same concept with cars. They build a stockpile based on expected demand and ship that.

 

There's no need to do so. If typical demand for a given region is, say, X battery packs per month, then that's how many will need to be produced and shipped to that region's distribution centers every month. Most component production lines are flexible, and can produce more than one type of a given item.

 

Your profile block does not identify where you are located so some options may not apply:

1. Continue with genuine Toyota battery service - prices have softened but you're looking at ~$3,000
2. Continue with current mechanic and Toyota battery parts - what did you pay?
3. Continue with current mechanic and Re-InVolt rebuild traction battery - ~$1,700 for the battery
4. Find another mechanic - in the San Francisco area, Art's Automotive or Lucious Garage. In North Carolina, David Taylor's shop (aka., Re-InVolt)

Now we know it is common practice to transfer the battery ECU from an old pack to a new pack. So trying to decode from the ECU identifier won't be very reliable. This leaves you with just the battery module numbers. If you will post some of the battery module serial numbers, we can give you an educated guess of their manufacture date.

First, supply some battery module serial numbers, they are just on top:

You can see the serial number in the white text of the center the module just to the left of the temperature sensor well. Just give us some module serial numbers.

Bob Wilson

 

He can possibly read them via the vent cover versus taking the battery out and/or removing the cover.

What battery error codes? For example, if a voltage sense line snapped, this could be repaired and possibly return the traction battery to service very cheaply.

BTW, I know someone who bought a full set of buss bars and sense wires that he did not need. Your mechanic might be able to 'do a deal.'

Bob Wilson

 

Since there has been so much chatter about Re-Involt and reliability issues, I thought I would weigh in this morning with some facts. We began our battery business in April of 2009 and to date have sold 263 Gen1 battery packs and 9 Gen2 battery packs. In the beginning, we sold 34 Gen1 battery packs with Gen1 cell modules and out of those, we have had 5 that did not last beyond the 1 year warranty period. There were 3 out of the 5 that failed due to electrolyte leaking and causing a P3009 high voltage leak code. The other 2 had cell modules to short out internally. We then switched over to using only Gen2 cell modules since we were not able to control the leaking electrolyte issue with the Gen1 modules.
Since switching to Gen2 cell modules, we have sold 229 packs, of which we have had 4 failures. Out of these 4 failures, only one was caused by a cell module problem, which made us tighten up our parameters for what qualifies as a good cell module. One was caused by an installer error, which we covered under warranty anyway and 2 were caused by mistakes made by us during the rebuilding process. One was a loose nut on a busbar and the other was caused by a stray bolt that found it's way onto the smr and blew the fuse. The bad pack that was mentioned in this thread, I believe was the unit with the loose nut.
We have not had any complaints to date that we have not gone beyond the call of duty to address. In several cases, we have gotten on 3 way calls with a dealership tech and our customers and walked them through the diagnostics to repair a non-battery related problem.
Will our batteries last as long or longer than the new packs sold by the dealer? I believe so. Has Toyota changed their design of Gen1 packs? Definately not. I just bought a 03 Prius with a new Toyota pack last week and the design is identical to what it was in 2001.

We are working on a new lithium replacement pack for the Gen1 and Gen2 Prius, so we will be able to offer a better solution in the future. Until then, we will continue to improve upon our procedures so we can market a great product at a reasonable price.

Thanks to all,
David Taylor
Re-Involt Technologies

 

Thank you David!

BTW, how was Green Drive Expo?

I had at one time considered an 'open' system for the Gen 1 packs. A plumber's nightmare, it would have opened the safety vent and converted the vent tubes into a means for keeping the cells wet but I soon realize this would not work:

• Excessive dV between the series modules - the electrolyte plumbing would have to maintain electrical isolation across the 270 V pack
• KOH is hideous stuff to work with - it is 'slippery', nearly invisible, and eats just about everything. Furthermore, it absorbs CO{2} and transforms itself into something that is not an electrolyte

Looking at the NHW11 module terminals, I don't see any way to seal them except possibly by some injected potting system. But then you're trying to put potting compound on a KOH coated surface . . . this is not going to work.

Very few things in life work perfectly the first time and there is something called the 'learning curve.' What is important is standing behind the product.

What I've found too.

This is interesting. Bringing in a new battery chemistry is a challenge and fitting it into the existing system with battery management . . . I can think of no one who I would trust more to do it right than David's team.

Bob Wilson

 

That is awesome. In one respect, I almost regret trying to maximize my current pack life.

BTW, I've found some well documented modules from an NHW11 just out side of Kansas city. The owner did the Toyota pack swap but fortunately he documented the module voltages in the first week of July and just e-mailed the six voltages . . . three weeks of sitting idle. I'd asked for three end modules, the strongest, and three middle modules, the weakest. They should be in Huntsville this week.

My first step will be to measure their initial voltages and then do a two-cycle, charge-discharge to measure their residual, Ahr capacity. Then I'll plot their self-discharge rate.

I am pretty sure that there is a lowest voltage limit that once reached from self-discharge, the metal hydride matrix becomes 'damaged' and loses any ability to store hydrogen. I was thinking of using a mob of AA cells for this study but then these six modules came available. One last technical question, if you have time.

There are scattered reports in "Prius Technical Stuff" about a 'balancing cycle.' One post claims the Techstream can command it and a couple of posts think the vehicle can 'do it on its own.' In theory, the sense lines might be used for a low-current, discharge to try and equalized or balance the charge. However, this begins to sound more like wishful thinking.

Have you run into anything like that with the current NHW11s? Some sort of built-in 'balancing cycle' that can be commanded? I could not find anything in the maintenance manuals.

Thanks,
Bob Wilson

 

Thanks Bob

 

Thanks for the information. Do you know how many of those packs have run past the warranty period?

No, it wasn't. The module terminal nuts were all tight. The pack was out of balance. The individual was advised to return the pack under warranty. Presumably, they did so.

it's true that the external appearance of the modules remains unchanged. However, I'm curious as to how you verified that the internal design and components of replacement Toyota packs - electrolyte, separators, plates, and so on - are identical to those produced in 2001. Can you shed some light on this?

 

We have dissected a new pack to the extent of cutting the cell modules apart for comparison. Toyota does have the glue applied directly around the terminals on the harness side only of the pack.
The pack we bought was 2 years old according to the date code on the cell module.
The date coding goes by the 4th digit of the battery serial number beginning with the letter "A" which signifies the year 1999.
It appears most assembly line cars came with packs built close to the year the car was produced. The exception has been the 2001 year model, which has date codes reaching back to 1999.
So far, we have not seen any date codes newer than 2008, even though we have had 2 packs that we have examined that were bought in 2010.

 

There are scattered reports in "Prius Technical Stuff" about a 'balancing cycle.' One post claims the Techstream can command it and a couple of posts think the vehicle can 'do it on its own.' In theory, the sense lines might be used for a low-current, discharge to try and equalized or balance the charge. However, this begins to sound more like wishful thinking.

Have you run into anything like that with the current NHW11s? Some sort of built-in 'balancing cycle' that can be commanded? I could not find anything in the maintenance manuals.



Bob, I realize this post is a couple weeks old, but if you havent seen it, here's toyota's TSB on "HV Battery Maintenance". This doc goes back to the old scan tool, but I believe Techstream will do it too.

Eric

 

So, does that sort of go with the theory that they made a bunch in 2008 to fuel the 2009 model year GenII and now are producing GenIII packs but the GenII are just sitting on shelves? Similar to maybe having GenI packs sitting around too?

 

Thanks!

This also read like the 'force charge' method where we mash the brakes and hold the accelerator down to put a charge on the traction battery. But two important aspects:

• run the car at least every 60 days - a warehouse storage challenge
• battery heating during charge - NiMH is exothermic

Thanks again,
Bob Wilson

 

I was referring to Gen1 packs so far as the 2008 being the newest. We have not bought any new Gen2 packs to view date codes yet.

 

Hello,

this is finally the info I was looking for... My Battery pack has the serial# 18XBHB03939D to 18XBHB03976D. According to your scheme this would make this a year 2000 pack, which makes sense as the first registration was in january 2001. Do you think the week or day is also coded in the serial# somewhere ?!?

ciao

Florian