How many years / miles can we expect battery failure?

[JKO]

Where can I buy:
LIM50E-7G and the LIM50E-8G.
http://www.s399157097.onlinehome.us/PDFS/LIM50E_Modules.pdf

 

[Phximiev]

Try the phone number at the bottom of the link.

 

[Vemund]

I couldn't find the answers in this forum.
I have a 2012 with 29k miles.
I'd like to have at least a ballpark of how much time / miles I have left until battery failure.

Probably many people wondering this, but there are few in the I-Miev's that has gone very far that I know of.

At my recent 4year/80.000 km (about 50k miles) service, my 2011 I-Miev battery was reported having 95% remaining battery capacity.
I suspect that the battery actually has more than 16kwh capacity when new, but that the reported remaining capacity still is a percentage of 16kwh, so my future degradation may appear to be quicker (pr. reported percentage).

I live in Norway, a cold country, a warmer climate will degrade capacity quicker (http://www.electricvehiclewiki.com/?tit ... acity_Loss).
The car has no issues with range, get around 100km at mixed driving (60-110km/h speeds), although a lot less in winter, sometimes all the way down to 60km range.

 

[JoeS]

Vemund, thank you very much for posting your data point. Interesting that while having the vehicle serviced you actually were provided with a capacity number. In any case, that's good news and aligns with my own experience with my 2012 i-MiEV being almost at 40,000 miles (64000km) having no noticeable degradation.

 

[ed5000]

I suspect that the battery actually has more than 16kwh capacity when new...

I got curious and after looking me68's canion readout I see that they're 88 cells at 4.1 volts each:

88 * 4.1v = 360.8 volts

And these are 50 amphour cells, right?

360.8 * 50 ahr = 18,040 whrs

which is 18 kwh! So there is a good "buffer" of a little extra battery there. :mrgreen:

 

[PV1]

We do have more than 16 kWh nominal capacity, but there is an error in your math. When calculating capacity in Wh, you need to go by the nominal cell voltage, which is 3.7 volts and not 4.1. So, 3.7 volts for 88 cells in series gets you a pack voltage of 325.6 volts, and at 50 Ah ampacity, that will net you a capacity of 16,280 Wh, or 16.28 kWh.

So, there is more than 16 kWh available, but not much. Our cars are probably more efficient at going down the road than we think, but it is absorbed by less than ideal charging efficiency (heating losses in the charger, quiescent electrical load from contactors and electronics, etc.).

 

[ed5000]

We do have more than 16 kWh nominal capacity, but there is an error in your math. When calculating capacity in Wh, you need to go by the nominal cell voltage, which is 3.7 volts and not 4.1. So, 3.7 volts for 88 cells in series gets you a pack voltage of 325.6 volts, and at 50 Ah ampacity, that will net you a capacity of 16,280 Wh, or 16.28 kWh.

Thanks PV1, That makes sense to use 3.7 volts since 4.1 volts doesn't last very long once disconnected from the charger. Especially once driving around for a while. Sorry if I got anyone's hopes up here. :roll:

 

[JoeS]

I have a 2012 and have noticed a big drop in range lately= I started with 80-90 miles after every night of charging, and now it is only 55 consistently...

ChaplainBill, are you saying that you typically fully charged your i-MiEV every night? How long have you owned the car? Did you typically drive it immediately every morning or did you let it sit fully charged for some length of time? Enquiring minds would like to know...

 

[Phximiev]

Ok, the iMiev temperature gauge reads: 115. My wife and I went 41 miles so far today and used 12 of the 16 bars. That computes to 54 miles for 16 bars. The AC was running full bore for all trips. Roughly, 13% off of the EPA range, but given the heat and the AC probably (maybe ?) within expectations.

I hear fans running all the time, but frankly still don't what's being cooled or not. When we park, turn the AC and radio off, a fan runs continuously. It ran for almost 10 minutes before it turned itself off.

Can't wait for some cooler weather.

And will it last? The battery that is.

 

[pbui19]

Ok, the iMiev temperature gauge reads: 115. My wife and I went 41 miles so far today and used 12 of the 16 bars. That computes to 54 miles for 16 bars. The AC was running full bore for all trips. Roughly, 13% off of the EPA range, but given the heat and the AC probably (maybe ?) within expectations.

I hear fans running all the time, but frankly still don't what's being cooled or not. When we park, turn the AC and radio off, a fan runs continuously. It ran for almost 10 minutes before it turned itself off.

Can't wait for some cooler weather.

And will it last? The battery that is.

was some of the AC air divert to the pack ? wow, 115F, toasty indeed. Do you have Canion to show pack temperature ?

Thanx

 

[Phximiev]

Not yet, but I am working on it. It actually hit 117 today.

 

[JoeS]

...It actually hit 117 today.

117degF = 47.2degC - and here I get worried when I see CaniOn reading 33degC . This is what gives battery engineers and management (who decided to forgo conductive cooling) nightmares. :shock: They may well have factored this in as the cost of doing business. The good news is that your active air cooling system kept running for a while and you still have plenty of years left on your warranty. As for those of us without CHAdeMO (or battery 'warmer') who don't have the fan inside the battery compartment... :roll:

So far, Mitsubishi has been excellent about replacing outright battery failures. Time will tell how battery degradation will actually be measured and supported by Mitsu, but extending the battery warranty to ten years / 100K miles is a good sign. (BTW, I haven't seen that in writing anywhere yet).

 

[Barbagris]

I have the same questions since we live in Phoenix. This summer has seen some very hot days, up to 114 over severals days, yesterday 112 or so. At the moment, we haven't seen any degradation, but we do wonder. Mitsubishi replaced our battery last December.

I also wonder, but can't find anything to support the notion, if Mitsubishi didn't make their battery more heat resistant over the last couple of years, given the Nissan lawsuit and their experienes. The LEV 50 appears to be 2009-2010(?) technology and it would seem that they could/would have done something to the chemistry since, but perhaps not announced it.

All very speculative.

A few months later, but... yes, in 2012:

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

 

[kiev]

From the article about the new cells:

These new cells retain 80 % of the initial capacity after 5,500 charge/discharge cycles (100 % DOD @ 25°C).

When buying a used C-Zero or iOn, go for the 14,5 kWh battery, the new cells are superior to the old ones used in the previous 16 kWh battery. And since the battery efficiency improved a lot (see the Ragone curve in the PDF documents) you’ll be able to get the same range.

As I said before the Mitsubishi i-MiEV kept using a 16 kWh battery but it also had its cells upgraded. When buying a used i-MiEV, chose one that was built after the summer of 2012 to be sure that you get the newer cells with increase lifespan.

Interesting info for sure.

 

[Phximiev]

Cool. This should mean that the battery that we replaced last December has the new cells. This of course raises the question of how one would check?

 

[PV1]

So, is that a hidden treat to those of us with earlier i-MiEVs that had a cell failure?

5,500 charge cycles, if charged daily, would be 15 years. Wouldn't that be nice :mrgreen: ?!

The LEV-50N cells actually don't have less capacity, the 14.5 kWh packs have less cells in them (80 vs. 88 for the 16 kWh pack).