Battery Failure Data

This topic is for posts about i-MiEV battery failure data (not individual's experiences). I'll try finding and moving those related posts in here when I get better connectivity.

Although I presently can't access it (on the road with an ancient iBook and obsolete crashing browser and miserable connectivity), this Google docs spreadsheet started by PV1 is a great vehicle for collecting information from those on this forum and will serve as the compilation of *our* data:

https://docs.google.com/spreadsheets/d/1INejOsxJ77ti_ZYgOd_oS2M7cQLnD1DuUFSPkACwD6A/edit?usp=sharing

For anyone reading this for the first time, the general consensus is that the i-MiEV battery pack is very reliable, has in general exhibited very little degradation, and 'failures' which have occurred that have been measured by CaniOn show only a single degraded cell within the battery pack. So far, Mitsubishi has been excellent about replacing outright failures under warranty.

I don't agree with the opinion of the very good reliability of the i-MiEV pack. At least for the 2012 year, because there are to much examples of failures. It´s possible that Japanese, Australian and European form 2010 and 2011 are more reliable, perhaps because they have, for sure, LEV50 cells. Maybe the 2012 USA models have the new LEV50N cells, and in the beginning some of them had some problems. LEV50N cells are more resistant to heat then the LEV50 and they should last longer, having clearly slower degradation rates, but I´m not sure if there weren´t problems in some cells in the beginning of their production.

LEV50N:

http://donar.messe.de/exhibitor/hannovermesse/2014/R732819/yuasa-li-ion-battery-datasheet-eng-295494.pdf

http://www.gs-yuasa.com/us/technic/vol9/pdf/009_01_026.pdf

So, forgive me to dare to present this opinion, but I began to believe that your 2012 USA models have the new LEV50N cells, but my 3/2011 European i-MiEV have the old LEV50. That can explain why I have some more degradation then what we see in most of 2012 i-MiEVs, specially developed when I used it without taking care with temperatures (now the rate is much more slower). But at least they seem more reliable, at least comparing with the first 2012 LEV50N. Now, its possible that they fixed completely the problem that they had in 2012.

I don´t remember if there is any discussion about the LEV50N cells in this forum. Sure was not here that I found the information about them (maybe I was unheeding).

So what do the 2013 and later have for batteries ?

I think that 2013 and after, all i-MiEVs have LEV50N, like the PHEV Outlander. Even the Peugeot Ion and Citroen C0 (the European clones) have the LEV50N since 2012 (I don´t know exactly the month of 2012 they made the change, putting just 80 cells on them). I believe that resistance to heat was very much improved in the 2012 and after i-MiEVs in relation to the 2010/2011 ones.

I bought a 2010 i 2nd hand 2 months ago, and in the 1st week i got it I had charging problems where 1 to 5 minutes into the charge it would cut out. If you sit inside you see a yellow exclamation mark in the dash before it aborts.

https://www.youtube.com/watch?v=QdsC6lWxiE8

This was under warranty as the car was less then 8 years old and less then 100.000km (57k). I just got the car back yesterday after it took 2 months to replace the traction battery. Unfortunately there was no spare in the EU, so one had to be ordered from Japan which takes atleast 6 weeks of boat travel to get here (NL).

So now I can finally start driving the i in honest.

Malm said:

I think that 2013 and after, all i-MiEVs have LEV50N, like the PHEV Outlander. Even the Peugeot Ion and Citroen C0 (the European clones) have the LEV50N since 2012 (I don´t know exactly the month of 2012 they made the change, putting just 80 cells on them). I believe that resistance to heat was very much improved in the 2012 and after i-MiEVs in relation to the 2010/2011 ones.

Click to expand...

"Summer 2012":

http://pushevs.com/2015/11/04/gs-yuasas-improved-cells-lev50-vs-lev50n/

We talk about it a little here:

http://myimiev.com/forum/viewtopic.php?f=23&t=2648&start=30

I'd like to see a CaniOn screenshot with cell voltages from someone who only has 80 cells. Do we know anyone with such a car?

I do. My friend's coworker just got a new C-Zero with 80 cells. The most important differences are smaller pack (14,5 kWh) and prolonged warranty 8 years/100.000 km like you have. He lives only 70 km away, so I can drive there and check whatever you need to be checked and post here. So let me know, exactly, what could be interesting. I want to know, for example:
1. Why the range remains the same even when the pack is 10% smaller?

databeestje said:

I bought a 2010 i 2nd hand 2 months ago, and in the 1st week i got it I had charging problems where 1 to 5 minutes into the charge it would cut out. If you sit inside you see a yellow exclamation mark in the dash before it aborts.

Click to expand...

That was interesting too that the 'fuel' gauge went from half-full to empty immediately when the yellow HV warning came on, thanks for sharing.

Great to hear that you got a new pack, let the fun begin...

It might be interesting to see the end-of-charge voltage, does it only go to 4.1 like with 88 cells?

Is it advertised as a 14,5 kWh pack or do they just talk about the range in brochures? Could the cells have larger Ah capacity instead?

I know that my C-Zero has about 14,5 kWh left in it's 88 cells now that's it four years old. It's still very much usable. Hopefully the new type cells really can stand the test of time better than the old ones, because less cells means more wear per each cell.

jsantala said:

It might be interesting to see the end-of-charge voltage, does it only go to 4.1 like with 88 cells?

Is it advertised as a 14,5 kWh pack or do they just talk about the range in brochures? Could the cells have larger Ah capacity instead?

I know that my C-Zero has about 14,5 kWh left in it's 88 cells now that's it four years old. It's still very much usable. Hopefully the new type cells really can stand the test of time better than the old ones, because less cells means more wear per each cell.

Click to expand...

There is a battery's label:




The label is here (red arrow):



Manufacturer diagnosis see 88 or 80 cells ("cellules") of similar capacity (near 45 Ah, "capacité actuelle"):




Info from a french electric vehicles forum:

Quelle est la capacité de votre iOn ?

Thanks, that's nice to know where to find the battery label. Hadn't noticed it.