A short rant, and some things I'd like to see changed to improve battery life

Remember a decade ago when Nissan dismissed the loss of capacity claims of Leaf drivers and so the Leaf drivers got together at a test track in Arizona and documented everything? Nissan lost and had to buy back their cars! Same thing will happen to Volvo too if they deny warranty for people who only lost 72% capacity!

 

i could have sworn another company warrantied capacity loss. hunday or someone

 

OK, I got it. But still my point seems to be valid. Read on to your next quote.

Yes, I agree there is still a wide difference in lines when only 50% discharge. But my point is that the max difference is at 20% discharge on the x-axis. When the battery is >80% discharged on the x-axis, you don't see any difference in Yeas to 80% capacity (y-axis) whether the battery is charged to 85% or 100%. And my second point is that most driver is likely to drive longer than 20 miles a day, thus depleting the battery >80% most of the time.

I used 30% as a benchmark because there is at least one case of a manufacturer who warrant the loss of more than 30% in less than 8 years as you stated. According to the graph, even charging practice of 85% upper limit (which is actual 76.5% SOC if the graph represents a 90% threshold), in 8 years, the battery is going to lose 20% capacity if it is habitually depleted to >80%. My contention is that most PHEV including Pip and PP probably lose 20% capacity in 7-8 years, but not more. And this happens on most Pip and PPs unless one is driving the car less than 80% EV range (less than 20 miles) daily. But losing 30% or more of capacity in that period is probably a very low-frequency event.

Yes, you can always find some cases of people who have lost capacity in shorter periods than average. But how many? Is that the norm? Again, even this case, which without reading the thread, is only a 15% loss after 4 years. That I think is well within the norm, and it is not much you can do to prevent this rate of degradation except not driving on EV mode any more than 5 miles at a trip.

As I pointed on my comment above, in the thread: 2021 Prius Prime traction battery: the first year degradation
I concluded that the PP traction battery degradation in the first 12 months of my 2021 PP was ~4.5%. If you read the thread, you will see that I did similar analyses on 2020 PP, and 2017 PP also. And they all showed a similar rate of degradation in the first 12 mo. But for the 2017 PP which is the only PP I kept longer period, this rate of degradation seems to have stabilized in the next two years so that it did not further degrade in three years.

Of note, those three PPs I have owned were charged by totally different routines. For 2017 I was doing daily commuting of 38 miles, so the car was on the scheduled charge to reach 100% EV range immediately before going out in the morning, and the EV range was fully depleted by the end of the day. Thus this would be similar to the 100% charge line on your graph. But with a lot more charge cycles (daily) compared to the other two. For 2020 PP, I stopped commuting, and for the most part of the ownership of the car for 10 months, I was under COVID restriction, thus the car was almost never charged fully. Mostly only 30-40% but was charged full occasionally (less than once a week) and driven the full EV range once a week. Thus this one is very close to the 85% charge line on your graph. And the 2021 PP was driven more frequently and charged more frequently (2-3 times/week) than the 2020 PP but not on the schedule. I just plugged the car whenever convenient and did not make any effort to keep the SOC level low even if I may not drive it for a few days. So, it is again similar to the 100% line in your graph, but worse than the use case of 2017 in that no schedule was used. In the end, at least for the first 12 months, the traction battery degradation rate is all very similar at about 4-5%. Yes, it is still possible that if I kept the car longer I may see drastic differences in the battery capacity in those three cars. But my guess is the opposite. It is most likely they all behaves very similarly all the way to 10+ years, that is because all three cars when I was driving, I drove it to deplete the EV range to 0 miles. Again your graph from the NREL report agrees with that assertion.

 

i think pretty much everyone here with a plug in has seen and discussed that part of the manual.

the answer is always the same, nobody does it. except volvo? i doubt anyone will buy a volvo because of toyota's disclaimer

 

Nobody warranties for range. Some do for capacity. While they are correlated they aren't the same thing. Some EVs will free up buffer capacity to counter capacity loss for instance.

1) Better education is always nice.
2) I think this is the norm with BEVs. Would be nice for PHEVs, but they generally already have larger buffers to contend with hybrid operation and emission warranty regulations.
3) Ironically, the gen3 had this. Since the gen4 Prime and PiP pack is air cooled, they used chemistries that are more heat tolerant.
4) That's the norm in Europe and other markets; it is called EV mode. In fact they don't have the full speed EV mode, but a City EV that is more EV. Both modes will kick on the engine for high demand.
5) The control algorithms will turn on the engine when it deems battery damage is possible; even the US EV mode.

Are you sure the 100% SOC means just to the bottom of the top buffer, and not a literal 100% SOC, cause I took a glance at some NREL papers, and they don't spell that out. The use of PHEV10, PHEV40, etc. also mean these aren't real cars. Most of these reports are form models backed by bench work.

Many of these statements are legal CYA. Not that some behaviors can cause capacity loss, but you can do everything right, and still have it. It is actually expected in Li-ion to have capacity loss in the first year with it just sitting there.

Some(most?) BEVs have such warranty. Seems rare with a PHEV, but as I mention above there are other concerns to the manufacturer in regards to the battery and its warranty. Having to meet the needs of hybrid operation and emission regulations likely means a PHEV battery is coddled more than a BEV one.

 

Actually my neighbor across the street bought one of those Volvos. And I've never once heard of someone coming to Priuschat asking for help after they read the manual... I bet ya I wouldn't be able to get someone to read their own manual even if I trapped them in a small box with the condition they have to read at least one page before they get let out.

 

Since we have established you can't trust Toyota to replace a failed battery under warranty and you don't want to get out while you can, then there is little more to be said.

 

i have always taken precautions. i try to charge just before leaving, and i leave it empty when away.

after 10 years and 85k (55k pure ev) i have lost about 15% best i can tell.

something sounds wrong with your charging, is it L1 or 2?

of course, cabin cooling is based on a number of factors, so it's hard to compare with others, or even one instance to the next

 

The Prime has an Battery Cooler option available in the MID settings. If that battery cooling option is selected ON, when the traction pack reaches 100 F and the car is turned Off, the MID will ask (for about 5 seconds) if you'd like to use A/C while charging. Though you have to be ready to select Yes, or turn the car on again and see if you get the option a second time after turning the off again. Many miss the opportunity the first time (it's a short 5 second screen) and second time around only works sometimes, for me, anyway.

As an aside issue many here at priuschat (mostly when Prime was first released in 2017) declared that preconditioning the car was useless to them, as it wasted charge time and electricity and didn't cool or heat (in the winter) the cabin for their comfort.
Anyone else remember those posts?