First, one would think (maybe wrongly) that one in 120 cells could suffer any of the faults you list and not render a large enough impact to be even measured. Second
E and F are subsets of c

Third.....you have still leveled a fair criticism. But I have to ask:

Surely Panasonic's QA wasn't such that every single pack would fail from so many different things!
I mean sure it won't be all of them from the same fault but it would be very surprising if battery pack failure causes were as even and random a split as you seem to imply.

But again...(much to probably both our frustration) we have no data other than conjecture that Honda and Panasonic would be making things such that they only failed for one or 2 reasons.
(EG an axle, 95% of the time, its the boot got ripped and the grease eventually got sullied.... or even an engine, most often its poor oil maint which ruins it, though failing at maintaining the cooling or ignition system or timing belt failure which also causes some to say bye bye)

You say the only measure the car has is temp and voltage, isn't there an amp meter in there someplace also? I read somewhere that when the BCM requests 40 amps and reads that it is only getting 36 (or some percentage), it triggers a code.


Also where Maxx ? He hasn't shown up to call you a HA shill and it feels foreign to have not had that happen yet hahah

 

And here is your fundamental lack of understanding:

If a SINGLE cell fails, it takes out a pack. Period. The vast majority of batteries are replaced due to a SINGLE cell failure.

Second, E and F are not at all subsets of C. Those conditions are completely independent of one another.

Third, QA has nothing to do with the nature of the beast. NiMH fails primarily in one or more of 3 ways: 1) capacity lost due to cycle wear, 2) SD, 3) IR. Panasonic can only take steps to mitigate the three. They can't get rid of them. If you use NiMH, that's what you get. Your reasoning implies that QA can somehow make gasoline not produce water vapor or carbon dioxide because they are undesirable. There are cause/effect relationships that exist because of physics/chemistry/reality.

Note that I did not mention capacity loss due to voltage depression. That's correctable, so I don't put it in the "failure" category, but it can absolutely be the cause of a failure due to the car's "deterioration" criteria, i.e., if so little capacity remains, it can trigger a code.

You weren't listening... "It can only see how voltages are responding to current at a given temperature."

Note the word "current".

Here's what you're missing...

The pack is monitored every 12 cells. This results in 10 voltage readings. The pack is managed based on the response of these 10 voltages to charge and discharge current, e.g.:

1) For given temp, if discharge current X results in ONE of the 10 voltages dropping to the specified minimum, pack is empty, stop discharging and force charge (this is a negative recalibration)
2) For given temp, if charge current X results in ONE of the 10 voltages dropping to the specified maximum, pack is full, stop charging and increase tendency for assist (this is a positive recalibration)

SoC is approximated based on the response of the 10 voltages to current when they're between the upper and lower limits. It's totally an approximation, and it's influenced by temp.

What happens when cell fails? "One of these things is not like the other, one of these things just doesn't belong." ONE of the 10 voltages is drastically different. The car sees this and triggers and IMA code and disables assist and regen. Why?

Because if you keep shoving current through a failed cell, it's going to get ugly. You're going to rupture the cell.

Typically the 10 voltages don't vary by more than 1% (0.2V on a 16V scale). IIRC, 0.6V is the threshold for the car identifying a problem... 1-1.2V difference is essentially a guarantee that you have a complete cell failure.

Those voltages are influenced by SD, cap and IR... the car has no idea which.. it just sees the end result.

 

it was 3am and I saw "voltages responding to current temperature."
no need to be mean about a simple misreading.

I'm hoping to yoink the battery in the next month or so and do like that other dude did to rehab it.

I know about cycle wear but could find no documentation on what is actually happening to cause it down at the molecular level.

 

Welcome back.

Sorry if I sounded mean. My "engineer voice" is very insensitive.

I was also a little frustrated by your idealized notions of how this stuff works and your seeming stubbornness to accept facts.

Just remember, 10 groups of 12 cells dictate how the car uses the pack. If one of those 10 groups differs by much more than 0.3V, **** starts to go South. At 0.6V, you're going to have almost no capacity and likely code a P1447. At 1V, you're going to code with either a P1447 or 1449 (more likely), and you have a failed cell that is a death sentence for the pack.

Once a cell fails, the pack is done.

 

Still doing the engineer voice thing? You're just upset I'm doing the same I suppose.

A fact you seem to not accept is that many people have succeeded in refurbing the batteries. Some haven't been so lucky.

Group A is a number. (Success)
Group B is a number. (Fail)
Group C is the sum of A and B

Math can be done to give a guess on if you're more likely to be in A or B.
You refused to admit even this which I find quite silly.

However, this is all beyond the OP of this so I'll let you have the last word and move on.


Partly more worrying is how the car has begun using the backup starter even though it was within normal operating (non-MIL) conditions not 2 months ago.

 

Not at all, but welcome back to a 3+ week old thread. Consider that I've owned 4 IMA vehicles. I have done a LOT of hands on work with upwards of 20 IMA packs and about 1,500 hours in research and hands-on reconditioning of Prius modules. I have data on over 2500 Prius modules.

I know the technology and limitations. You don't, and you appear to believe that long term limitations of a technology can be overcome with hope. Even when told how the system works, you argue.

What YOU don't realize is that MOST people haven't succeeded in refurbing the batteries.

Hybrid Battery Repair went bankrupt because they couldn't make it work.

Falcon doesn't have the best reputation because they have such a high warranty rate because they don't succeed. A lady on here received 3 batteries for her HCH2 in 4 months because they kept failing. Fewer and fewer organizations are offering reconditioned IMA batteries with anything more than a 90 day warranty.

What you never hear is: "I reconditioned my battery two years ago, and it's running great!"

What you hear is: "I did it and the car is better than ever." You never hear the follow-up. When you get that feedback, it's 3-6 months or less.

IIRC, your own experience with a reconditioned pack is not what most would consider long-term or particularly successful.