Realistic battery life

Doing it that way will buy you time. Could be years, months, weeks, or even days. You are playing what I call "whack-a-mole"



You fix one and it is a very temporary fix. Then another will go. You fix it and it is temporary. Then another. It just keeps repeating and never ends.

The Prius doesn't care much about the capacity of the pack. What it cares about is the difference between the blocks within the pack. If all the cells are equally crap and have 15% capacity left and 400% the internal resistance no error codes just poor fuel economy and quick charging and discharging. But we don't live in an ideal world where things age identically. There will inevitably be variations, even very slight variations which will eventually cause a code to be thrown.

When you replace a single battery module, to get the best results you ideally want a matching battery module. It has failed (Techstream will tell you which block and then you can measure which of the 2 is the more bad one) so this battery module is no longer like-enough to the other 27. You need to find 1 battery module that is like-enough to those 27. If you replace the failed 1 with a brand new battery module, you will immediately get failures. It is too dissimilar to the rest of the pack. The game you have to play is to find a battery module on the used market that matches the 27 you have in the car. Usually you will fail at this. How good your match find is, is how long it will last. Hence the days/weeks/months of potential fix time.

This is why the most reliable way of rebuilding a pack is to collect thousands and thousands of used modules. Test and characterize each one. You can then statistically find 28 from this sample set of thousands that is quantitatively similar enough to make a single pack. It will still have low capacity and high internal resistance. But they will be pretty equivalently terrible which is all the car asks for.

Now here's the problem. In the peak of rebuilds finding thousands of modules wasn't too hard. You had a good mix of new cells and old cells. High mileage new ones, low mileage old ones. Ones that lived at high temp their whole life, ones that were barely used in a mild climate. So finding a match was possible. Today, there is almost no surplus. There are lots of companies that offer this service. About 2 or 3 of them are big enough that they can still do this. All the fly-by-the-night mechanics that do it on the side, may have 5 or 10 packs sitting around. Finding 28 matching modules out of 280 is pretty difficult and they usually don't last long.

If your goal is to fix it and unload it to someone else you really don't like, then the whack-a-mole approach with balancing will buy you the time.

If your goal is to actually keep the car, then get a new battery. You only have 2 options. Buy the one from Toyota or buy the one from me. Both require DIY in the battery. Even if you were to buy a Toyota pack at a dealership if you drove to the US you could get it done in the $2500 - $3000 range.

 

One of the first things I did when I bought my Gen 2 Prius a couple of years ago was open up the side panels and check the HV battery fan. I was fortunate that it was relatively clean, a light layer of dust only, but I took it out and scrubbed it down anyway. I guess it's not likely that either of the 2 previous owners of my car traveled with any pets, because I have seen examples online of how clogged with pet hair a fan can get, especially the Gen 2 cars. I don't know if you were able to see what came out of your car's fan, but I would be curious to know. Perhaps there are other circumstances apart from having pets in the car that can cause a fan to be clogged. In any event, if your car had been operated for a period of years with insufficient cooling of the HV battery due to a compromised fan, I would suspect that would be the main culprit for your premature failure. If you are considering spending money to fix the car's battery, I would guess you really like the car, apart from the current battery issues you are having. With its relatively low miles, it should be good for many more years once you take care of this "Achilles heel". I would definitely recommend going with the new battery from Toyota or @2k1Toaster rather than any of the alternatives. Just keep an eye on that fan from now on.

 

It sounds like you need either a brand new car or a brand new pack. There are a few places in Texas that should be able to broker you a brand new OEM battery pack and maybe even do the install cheaply. At least get the pack for you. Lots of places don't sell to "normal people". The only other option for a new pack is me. I will ship to MX but it costs more than shipping to the Texas border and you picking it up (which is FREE).

I wouldn't use the word weird, that was the design goal! Yes they fit the original prismatic pair-of-modules footprint and replace each pair of modules with a single module. 6 cells per pair of original modules for 12 cells total is equivalent to the 12 cells in my single module.

Like you said, battery life and warranty have minimal relationship. Keep in mind that Toyota now gives a 1 year unlimited miles warranty on their batteries that aren't installed at a dealership, and 3 years unlimited miles on a battery installed at a dealership. They also give a 36K mile warranty on the engine. Doesn't mean it blows up at 36,001 miles.

Warranties mean liability. The time of a warranty offer is directly translated to cost of the liability for the business. Toyota, a multi-billion dollar business, offers less warranty than I do in your case (21k miles in a year for you).

The only two options for new batteries that perform like new original batteries are Toyota and myself. Any other battery is going to be a rebuilt. That the difference of putting a salvage yard part on versus a brand new part. Salvage yard part will work but will fail much sooner. It already has lived a healthy long life before you even got it.

Nobody but a fool changes their battery every 1-2 years. Those fools are anyone that buys a rebuilt or used battery. Brand new battery should last you just as long as the original.

I've got my packs in taxi's that do way more miles than you in a year without issue so far. Same with Toyota.

 

They aren't the same, but pretty much as close as possible.

You can order on the website and pay via credit card if you want. If you're driving up to Texas you may want to check local dealerships there to see what they can do for you on a dealer installed Toyota battery. If you don't want to DIY, that's your best option. If you're up for the DIY, just make an order on the site.

 

I've been rebuilding the gen 2 batteries for several years now, and my opinion is the batteries are lasting from 9 to 11 years. Ocassionally there are some outliers where the early gen 2 batteries have made it for 13 to 14 years but that is not the norm for sure. I have seen a few gen 3 batteries around the 6 year mark but only a couple. Toyota's prices have come down slightly on new Panasonic batteries in my area, and that is definitely an option for people who can afford it. Most people; however, don't/won't/can't spend that much on a car that is 10 to 15 years old and worth a few thousand dollars. If your car is in good condition and has been serviced regularly, regardless of the mileage, dealing with replacing/rebuilding/reconditioning the batteries is going to be part of owning hybrid/ev vehicles, so not everybody's situation is the same.

 

Another reason to avoid old hybrids

 

That has to be costing Toyota a fortune in carb states

 

I also think that 9-11 year expectancy can't be true. In Europe every Toyota hybrid that is serviced at the stealership has a waranty on a battery for 10 years + extra 15k km or extra year whatever comes first. It would cost Toyota just too much money if it were true.

 

I think it depends how u use it. I bought my prius 2012 with 320k km from taxi driver, he changed battery on 250k, problem was in fan, it was just very dirty. I think u have to try to change just damaged ones and not whole battery.
Good luck!

 

I think it depends a lot on how you take care of it.

 

I thought I would post a couple case studies on here of gen 2 batteries we rebuild....for the fun of it...to show long they’ve survived and how long they last after rebuilding and reconditioning.

Case #1. Dentist
2006 Prius
Original Battery (Date Code G, Mfg. 2005, not rebuilt previously)
Mileage: 176k
Car Condition: Clean
Location: Central Midwest, KC
Notes: This battery presented with two failed modules. Typically there is only one. We replaced bus bars, rotated modules (moved outside ones in and inside ones out). We do this by marking the first, 14th, 15th and 28th modules, and start at the 28th place with number 14 to number 1 then 28 to #15. And we place the bad modules with good ones at the service end.

 

Late to the thread, but I would say we have zero info from Toyota about how long Gen3 batteries are lasting. Going back to the 2013 time frame, there was a Consumer Reports batt survey, so we knew some trends for the Gen2's and Gen1's. Also in that time frame there were comments by Toyota that less than 1% had failed, which was generally consistent with the CR data. Of course some older model years, when numbers of sales were lower, were approaching 5-10% fail rates (higher now of course), but that was averaged out by all the new Prii on the road. Anyways we have no recent quotes from Toyota.

My sense is Gen3's are lasting longer due to some logic improvements protecting the battery from getting too low charge (eg; during empty fuel tank scenario).

We are at 12-yrs and 180K miles and HV batt seems fine.

We also did some semi-useful PriusChat surveys for Gen2, so it might be useful for Gen3 at some point. PriusChat we tended to see higher % of batt fails than Consumer Reports quoted, but of course the participants here are often here becuase they are dealing with batt issues, so surveys here are hard to remove bias..although @uart tried to design a survey to remove the bias and still was on the high side.

 

Just wondering how many original gen 2 batteries are still in service, and haven't been accounted for in your estimation because you and everyone else has not seen them yet. If you are still rebuilding original batteries at the same rate ten years from now, then you would have to revise your estimate upwards by a few more years.

Is the rate of original gen 2 battery failures now level and peaking, or is it still rising, or is it already falling? In the absence of a truly representative sample group, that might be the best way to estimate average original battery life.

 

I wis

Im not sure because I didn’t start keeping track until we were trying to follow some new non-Panasonic modules we imported from Japan. But now I am (as much as a little place in the Midwest can) keeping track of every one. I’ll post more as they come in. I would say the original failure rate has been steady for gen 2s I’ve worked on here.