Don
Site Moderator
Posts: 2835
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Battery Degradation

Wed Oct 31, 2012 5:48 am

oakvilleblake wrote:Have had ours for 2 months and the range has improved noticeably over time.
I don't think that's the car . . . . or the battery - I suspect it's the result of the driver learning how to drive the car for best ecomomy and range. Too bad there isn't a similar training program for those with ICE powered cars ;)

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

spirit
Posts: 7
Joined: Tue Aug 21, 2012 4:33 pm

Re: Battery Degradation

Tue Nov 06, 2012 8:26 am

I found this interesting. I wonder if they changed battery packs since then. Anybody know?

http://www.greencarcongress.com/2008/05 ... y-pac.html

alohart
Posts: 377
Joined: Wed Apr 25, 2012 10:15 am
Location: Honolulu, HI, and Uppsala, Sweden

Re: Battery Degradation

Tue Nov 06, 2012 10:29 am

spirit wrote:I found this interesting. I wonder if they changed battery packs since then. Anybody know?

http://www.greencarcongress.com/2008/05 ... y-pac.html

There were a flurry of reports in summer, 2011, about Mitsubishi agreeing to use Toshiba SCiB cells in its i-MiEV and other future EV's. But there are also references to the i-MiEV using cells produced by the Mitsubishi-Yuasa joint venture. Maybe Toshiba wasn't able to provide SCiB cells in time, in sufficient quantity, or at an acceptable price. Or maybe they're used in some i-MiEV models but not all. I suppose until i-MiEV owners examine their battery packs closely, we won't really know for sure.
Aloha,
Art
Honolulu: 2014 BMW i3 BEV (formerly 2012 i-MiEV SE)
Uppsala, Sweden: 2000 Honda Insight

Vike
Posts: 401
Joined: Sun Jun 10, 2012 8:25 pm
Location: Albuquerque, New Mexico

Re: Battery Degradation

Thu Nov 08, 2012 12:29 am

alohart wrote:There were a flurry of reports in summer, 2011, about Mitsubishi agreeing to use Toshiba SCiB cells in its i-MiEV and other future EV's. But there are also references to the i-MiEV using cells produced by the Mitsubishi-Yuasa joint venture. Maybe Toshiba wasn't able to provide SCiB cells in time, in sufficient quantity, or at an acceptable price. Or maybe they're used in some i-MiEV models but not all. I suppose until i-MiEV owners examine their battery packs closely, we won't really know for sure.
As I understand it, the problem with SCiB is weight, about 50% more than the GS Yuasa for comparable storage. Mitsubishi does use SCiB for a shorter-range model in Japan, where it appears some buyers are more willing to trade range for a more durable battery with greater tolerance for quick-charging. I'm guessing the fact that Japan has a relatively extensive network of CHAdeMO Level 3 chargers makes it easier to live with lower RR numbers, especially if you're comfortable slamming your batteries w/CHAdeMO a couple times in a day (as Toshiba says you should be with SCiB).

In the U.S., we only get the maximum-range battery pack made by GS Yuasa. Given how much grief reviewers heap on the i-MiEV for falling several miles short of the LEAF range-wise, limiting U.S. models to "max-range batteries only" makes sense.
Last edited by Vike on Fri Nov 09, 2012 11:29 pm, edited 2 times in total.
2012 Silver ES w/QuickCharge+DRL/foglights, Eaton Level 2 EVSE, since 9/9/2012

spirit
Posts: 7
Joined: Tue Aug 21, 2012 4:33 pm

Re: Battery Degradation

Thu Nov 08, 2012 6:49 am

15% loss over 3 years, providing you recharge every day, is a lot. I am not sure what constitutes a cycle in this case.

BillThompsonMIEV
Posts: 137
Joined: Thu Jul 19, 2012 8:43 pm
Location: San Antonio, Texas

Re: Battery Degradation

Thu Nov 08, 2012 6:28 pm

The consensus on this thread is that battery degradation is not happening. My question is what will the indicators be of such degradation? Will it be not showing 16 bars after a full charge? Will RR after a full charge drop dramatically after a full charge?

spirit
Posts: 7
Joined: Tue Aug 21, 2012 4:33 pm

Re: Battery Degradation

Thu Nov 08, 2012 9:04 pm

I am thinking that would be correct. I am thinking we would see this 15% drop after 45-50,000 miles or earlier. It would depend on the definition of cycle. I would think the BMS would extend the life quite a bit longer. I wonder what the real world test results were.

peterdambier
Posts: 284
Joined: Thu Oct 04, 2012 3:26 am
Location: Bergstrasse, Germany

Re: Battery Degradation

Mon Nov 12, 2012 3:49 am

We have bought our i-MiEV with some 4000 kilometers. Range used to be 107 Kilometers. When we bought the car, the battery was completely cycled to recalibrate. Since then range used to be 140 kilometers and even 164 once.

Some 2000 Kilometers later and after the update, range is 100 kilometers. Panic?

I remember we got only 85 kilometers after a full charge but 30 kilometers later it was 91 kilometers.

We used to note every kilometer in a book and count and guess. Today we have become electric oldtimers (3 month :)

We have been on a pirates convention, driven some 204 kilometers with the biggest distance 111 kilometers and the turtle was giving us a fit twice. I am sure she would have carried us the final 9 kilometers but not without complaining.

I stopped filling the batteries to the rim. We are living on the backside of a hill and 1/3 down. So after driving some 10 kilometers the batteries are full and the real voyage can begin. But remember we have to get up the hill again.

It is winter and we have bought a pants warmer for my wife, 12V 50W. The fan is constantly running to keep the windows open and we even use A/C and heater sometimes. Counting and guessing again it is still the same 120 kilometers. It needs a year at least to see if there is a loss and dont forget, driving habits changed too.
Peter and Karin Dambier, DL2FBA, www.piraten-fraktion-bergstrasse.de

JoeS
Site Moderator
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Location: Los Altos Hills, California

Re: Battery Degradation

Mon Nov 12, 2012 1:41 pm

peterdambier, thank you for your writeup, although I did cringe when you mentioned Turtle. :shock:

Using the Range Remaining readout after fully charging the iMiEV is not a good way of assessing battery capacity. On the RR readout after fully charging we have seen a high of 103miles (166km) to a low of 35 miles(56km), all with relatively new vehicles, simply indicative of how efficiently/inefficiently people drive. I have yet to see the same RR number repeat whenever I fully charge the vehicle.

Quite frankly, if my iMiEV lost 20% capacity I probably wouldn't notice it as simple variations in my driving behavior exceed this number.

I'm hopeful that our CAN investigators will come up with some battery capacity information that may be stored in the vehicle.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

fjpod
Posts: 529
Joined: Tue Apr 17, 2012 2:31 am
Location: NYC

Re: Battery Degradation

Mon Nov 12, 2012 2:35 pm

Since the weather has turned a little colder here in NY, I think my RR number after a full charge has decreased...but I am also driving the car a little harder out of necessity.

I don't think I will know if it is real battery degradation or just the other factors at play, until next spring/summer.

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