Engine Strain 200k city vs highway

Oops, I meant Daewoo.

 

Here's another chart from the same DOE study showing the end of life (160K) battery capacity.
It's interesting how the Prius fare worse in this test.

How will the PC spinmiesters respond to this ? The CR long term Prius battery test was nothing but a stupid publicity stunt, yet it was well received with approval by the above average intelligence (self rated) folks here.

 

For starters, how about posting the ORIGINAL DAMN LINK to the appropriate `DOE`site!

When you say DOE you could mean, ANL, ORNL, INL, etc etc

Thank you

 

I don't know what that end of life test means.

I can read the first graph you posted, though. Looks like after the first year the gas consumption all but flat-lined for years after that, an incredible affirmation of the Gen II (in this user's case)'s ability to deliver low consumption through hundreds of thousands of miles.

 

I can't make sense of that battery graph because everything I've read says you can't use 6.5 amp hours of battery in the Prius.

 

The chart has an INL logo.

That is interesting data, by the way. Mostly it just makes me skeptical of *EV cars where drops in capacity are going to be very obvious to the driver. I know the chemistries are different.

 

Exactly what I think. A substantial drop in capacity of a Prius battery probably doesn't actually impact gas economy that much, since it's rarely hitting the top and bottom of its capacity in normal use, but for an EV car it's going to have an undeniable impact on its range.

 

Assuming the data is correct and typical (a big IF), the preserved capacity of the IMA batteries despite widespread reports of higher failure rates than HSD batteries makes me wonder if one company can learn from the other or if we are looking at a trade-off.

Who wudda thunk that tp would post something interesting ?

 

I presume INL isolated the battery for testing. Odd that each battery of the same model are so similar, it reminds me of memory effect.

 

I found the report here (warning: PDF). It says the two Prii averaged 39.2% capacity remaining, which is a little less than what is actually used, according to hobbit. It also says that the max initial capacity was not measured:

So those two numbers may not be comparable.

BTW, it also says an Insight's battery failed at 72,000 miles.

 

Thank you!

It is interesting that tpfun did NOT post the link to that report. Perhaps he did not want to disclose the comments on page 3 of the report in regards to end-of-life battery testing

"Therefore, it is reasonable to conclude that the
battery’s ability to absorb energy had not degraded as a
result of 160,000 miles of fleet testing"

Huh

So INL reached the conclusion that even after 160,000 miles of "fleet" testing, the battery ability to absorb energy had not degraded. This is also borne out in real-world use of Prius as taxi's, especially in a harsh climate like Winnipeg Manitoba. Summer highs of upper 90's F, winter lows of -40 F

 

:focus: and back to the OP - if you don't mind.
I would *never* buy a VW, ever again. I had a Polo 1.4L TDI 2002 for 7 years. Total 80.000km.
I serviced it as per VW plans only at VW services. I used only original parts/oils etc. The result?
In the first 2 years of ownership, during the warranty, I had to had the car services multiple times, the engine had to be completely be opened to fix a non stable camshaft, my windshield cracked by itself, the A/C compressor was changed, the oilpump case had to be changed.....
Then after that, I had to spend an additional 3500€ in repairs (brakes changed at 50.000km, suspensions support changed, the exhaust had rusted, rear windshield wiper motor rusted (!)) and regular service (500€/year including the 2 years warranty, otherwise it would be higher over the 5 years period). The A/C never worked properly - it would turn on/off briefly and repeatedly for no reason every now and then - they never managed to fix it and once they asked me 2000€ to fix it (!!).

Granted, I was never left stranded, but I never felt sure about my car. Plastics, body build, interiors were pretty good. It looked new when I sold it. But it was enough to decide never to buy VW again. Ever.

200k mi over a period of what? 10 years? that's a lot on any car. The positives of the Prius is that mechanically is *way* simpler than any other car out there. Both in the transmission and the engine: no clutch (and that's expensive to change...), no accessory belt, no hydraulic coupling, no turbo, no high pressure pumps; the engine can run smoothly independently of load, no gear change, no push/pull from a transmission, etc. I think the Prius is as smooth as it can get. Only a direct driven EV vehicle (electric motor drives directly the wheels) can likely be simpler.

Regarding fuel consumption some data from Europe (from spritmonitor.de) - these are average values (in L/100km):

Prius (from 2002):
number of cars in DB/min/avg/max
457/3,65/5,19/6,75

VW Golf TDI (with at least 100HP since 2002):
1378/3,67/5,90/12,31

These are Golf TDI with 250.000km on them (and that's a LOT for EU!) at least.

This guy has a 450.000km on his TDI - you should contact him (he might know english). He bought it in 2004 used with 62.000km on it and now flying at 430.000km.
This other one, 280.000km since 2005.

This other user instead has 250.000km on his Prius 2nd gen.

I would ask the VW owners how much they have spent and what they had to change on their TDI engines, beyond what required from the VW service plan.

 

That's why he's trashing prius fun!

I don't know what's wrong with VW. They are a huge seller international but not so well in the US. I've read in multiple places now that the 2011 Jetta is uncannily inferior to its predecessor, like VW really skimped so much on money that other than a little bigger or whatever it has removed the joy of owning a VW (they do drive well). And quality for VW has been poor for years now. I think they used to have a notoriety of quality, which I guess was squandered starting about a decade ago. Isn't that when they created that $70k luxury VW, the Phaeton?

 

The INL study measured Ah from "full SOC recommended by the manufacturer" down to 1.0 volt average. So some of the difference in "remaining capacity" between the cars may simply be explained by different starting points. Moreover, I think that the measured capacity was from a point below full to a point higher than empty compared to the start and end points that give 6.5 Ah from the battery manufacturer.

Perhaps Jayman can clarify.

 

I'm sorry to hear that. Once you have a bad experience with a brand, you likely will never go back to it

I had a similar horror story with a 2000 GMC Sierra truck I purchased for work. The 5.3 litre V8 started knocking and using oil during the first 3,000 km

Guess what General Motors told me?

They said a motor knocking, and using up to 1 litre of oil every 600km, was NORMAL!

Had many issues with that vehicle. Would not drive a GM brand vehicle if I was paid to do so!

It does appear they are contrasting technical capacity, not useable capacity. Also interesting they did not establish a baseline when the vehicles were new, but rather depended on manufacturer technical specifications

Still, they did provide that quote, which tpfun conveniently forgot to include, that at the end-of-life test the batteries were still in good shape.

 

Jayman, how closely does a change in max discharge rate track with capacity ?

 

Total capacity or allowed capacity range? Remember the Prius keeps very tight control over the allowed battery state of charge

There may be a significant, approaching a logarithmic rate of change, discharge rate vs capacity change

But according to the entire INL report that tpfun apparently forgot to post, that resulted in a very minor change in overall performance and fuel economy of their test Prius

There are Prius taxis slogging around Winnipeg with hundreds of thousands of miles on them. They are far more likely to get written off due to a crash

 

^^ Jayman,
I was reasoning that if a change in maximum discharge rate correlates with a change in capacity between two defined end-points, then finding no change in the former implies no change in the latter. I want to ignore the capacity graph because I really do not know how to interpret it without baseline measurements.

 

The report doesn't say that at all.

 

Correct.

No, but this report

http://cta.ornl.gov/TRBenergy/trb_documents/Lee Slezak Presentation TRB PDF.pdf

does

Do you have any more creative interpretations?

I should warn you I have been involved in scientific research (ORNL, Sandia, LLNL, ARPA) for most of my 22 year consulting career.

One of the worst things you can do is take snippets of data, such as those battery capacity charts you posted, take them out of context, and arrive at wild conclusions

There is a very clear reason why you did NOT post the entire source article, in which INL concluded the change in end-of-life battery capacity did NOT impact battery performance