Could Nissan's battery problems happen to us?

Mitsubishi i-MiEV Forum

Help Support Mitsubishi i-MiEV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

gmarcucio

Well-known member
Joined
May 15, 2013
Messages
91
Location
Hagaman, New York
Do you think the issues with Nissan Leaf's battery packs could become an issue with our MiEV's? How would Mitsubishi handle it?

http://www.mynissanleaf.com/viewtopic.php?f=4&t=13331
 
I don't think so. We have several factors in our favor. The first being an active thermal management system using a fan and air blown through the battery pack. While not as good as a liquid thermal management pack, it has kept our batteries cool even in the South West. We have not heard of any i-MiEV suffering the same fate as the Leafs. The Leaf in contrast has no active thermal management sytem whatsoever. The second, is our i-MiEVs use a single horizontal plane of batteries while the Leafs use a pancake stack of batteries. As the heat rises from the bottom battery in the stack, it starts cooking the top battery while the very top battery is getting roasted. Over heating a lithium battery will cause permanent damage that can't be recovered from unlike extreme cold.
 
There's also the fact that the Leaf's LiPo battery chemistry is significantly different from the Yuasa LiMn chemistry in the MiEV. I don't know if that counts for or against us, but it is different...
 
What's amazing to me is that they have 55 pages of posts, and not much of a consensus of what Nissan's battery replacement program vs. their $100/month battery lease (?) does. Nissan is doing very poorly in their communications with their customers. Then again, from what I'm finding on the Internet, this is nothing new from Nissan.
 
Another thing I thought of about on this thread - the few battery issues that have surfaced with the i-MiEV, MMC seems to resolve them quickly without blaming the customer and forcing them to go through a lemon law to get their car fixed or replaced. That was the only way those that suffered degraded batteries in the Leafs to recover from this fiasco.
 
Unfortunately we don't have any cooling system on our I-mievs. The only way you get the fan is if you have the quick charge port or the battery warming system. The warming system only operates when the battery is extremely cold and it puts heated air into the pack. For cooling, the system is only used during quick charging. I found this out because I leased a I-Miev with the warming system and was able to simply modifiy it to provide cooled air from the A/C system in the summer. I liked it so much I bought a I-miev (because the residual on the lease is so high and Ally will not discuss changing it) and to my surprise, there is no cooling fan whatsoever or ductwork into the battery on my car or anything else the dealer had in stock. They thought all of the SE's had the fan but all the cars they had were SE's and non had the fan. Therefore, like the LEAF, the battery just sits there a cooks. On hot days in Florida, the battery is well over 110 degrees which I can drop into the 80's with the A/C. My new I-miev is just parked with 60 miles on it until I figure out what to do to get cooled air into it. Mitsubishi doesn't sell parts for the pack as all the cars are still on warranty so I am stuck for now--not really happy.
 
siai47 said:
Unfortunately we don't have any cooling system on our I-mievs.
This seems to be in direct conflict with what Mitsubishi says.

http://www.mitsubishicars.com/MMNA/jsp/imiev/12/electric-car-battery-and-charger.do

Scroll to the bottom, left side, where it says, "Two Lithium-Ion Cooling Systems." Go ahead and drive your car. :cool:
 
aarond12 said:
This seems to be in direct conflict with what Mitsubishi says.

http://www.mitsubishicars.com/MMNA/jsp/imiev/12/electric-car-battery-and-charger.do

Scroll to the bottom, left side, where it says, "Two Lithium-Ion Cooling Systems." Go ahead and drive your car. :cool:
"The custom-made battery pack on the ES trim of the i-MiEV features a fan-driven, forced-air induction system that automatically engages to protect the battery from overheating during charging."

What about those of us with SE's? And even the ES's battery cooling system functions only during charging, not during normal operation, so this cooling system wouldn't keep the battery pack cool when driving in very hot weather.

Maybe the different arrangement of the battery cells and the different chemistry compared with the Leaf makes our battery packs less susceptible to heat. I'm not aware of any battery pack problems experienced by i-MiEV owners in places like Arizona where Leaf owners had problems.
 
I hate to comment about this again but there is no cooling fan in the I-miev unless you have optional equipment. Even the dealer was confused about this as I went back and complained about the lack of a fan after buying the car. Careful reviewing of his sales handbook clairified the fan sitiuation---You must have either the battery warmer or the quick charge option to get any kind of fan. I know I have read comments from Mitsubishi spokesmen talking about the two cooling systems however, they just aren't there. On my car with the battery warmer, the fan runs for a couple of seconds each time the EVSE is connected. The car without the warmer does nothing (noise wise) when you plug in the EVSE. I found the harness coming out of the top rear of the battery pack the runs to the fan. On my other car, there is a rubber plug in the same spot where the fan wiring harness would be. Also, the air the fan draws through the pack comes in from a duct located under the passenger side carpet. The duct then goes through the floor and into the battery pack. One car has all of this stuff and the other car has none of it. Even if you have the fan, it is useless for cooling the pack (if you have the warming system) and only operates during quick charging to cool the battery. After that, it doesn't do anything.
 
I have an SE model. Look at page 7-6 and 7-7 of the owner's manual. It shows a coolant reservoir in the rear of the car in the electric motor room. Manual also states same type fluid added to it as to the hot water heater reservoir (see page 7-10 of manual). Why is this reservoir in battery compartment, if there is no cooling process?
 
BillThompsonMIEV said:
I have an SE model. Look at page 7-6 and 7-7 of the owner's manual. It shows a coolant reservoir in the rear of the car in the electric motor room. Manual also states same type fluid added to it as to the hot water heater reservoir (see page 7-10 of manual). Why is this reservoir in battery compartment, if there is no cooling process?

This is the cooling system for the motor and the charger I believe, not for the battery.
When charging, I can hear the coolant pump cycling on and off once in a while. The hoses going into and out of the pump in the back are warm, just barely, so it is doing something.
 
The liquid cooling system you are looking at cools three things---the onboard charger, the inverter and the drive motor. This is just like the LEAF that has liquid cooling for those same components. As far as the battery is concerned, on the standard car, our cooling system is identical to the LEAF---there isn't any cooling system---there is no air or coolant going into or out of the battery pack. Time will tell if we are just lucky or there just isn't enough of us our there to have had a noticable problem. If you have ever looked at pictures of the inside of our pack, the battery modules are really packed in tight with very little room for cooling. The LEAF battery appears to have more space between it's individual cells then the I-MiEV. Maybe our battery chemistry is just a little more tolerant to heat then that used in the LEAF. In my opinion, Mitsubishi (like Nissan) dropped the ball on this one except Mitsubishi alludes to the fact that there is a cooling system. I also believe that the LEAF population is the Canary in the coal mine on this one. It took about a year to start showing up, first in Phoenix, then in Texas and other parts of the southwest. Now as another summer is here, it is also happening in California and in Florida--just a matter of time.
 
One point that hasn't been mentioned yet -- Nissan's instrumentation is suspect.

I still own my Nissan LEAF. I'm letting it "summer" in Fremont, CA by loaning it to my sister. It spent two summers in Fresno, CA, where July temps hit 110 degrees and stay hot all summer long. I need to wait until January 2014 before I can sell it without losing significant money from the CARB and San Joaquin Valley Air rebates (they require three years of ownership).

Now, about instrumentation -- Nissan has had at least three service calls on the LEAF where they've reprogrammed the instrumentation (including what Mitsu calls the RR and the LEAF battery capacity gauge). If you read the LEAF forum, you may notice that there are several aftermarket devices to read the CAN bus. This started happening when owners realized that we couldn't trust how far the car said we could go, how hot the battery pack was getting, or how much capacity the car was losing.

Add to this the fact that Nissan representatives (as well as dealers) have given misinformation about the car over and over again. Some of them still say it will go 100 miles on a charge. They don't say that this would take driving slower than 99% of drivers are willing to drive. When my LEAF lost it's first battery capacity bar, I asked their rep what that meant. Has it lost 1/12th of the battery capacity (since there are 12 bars)? How about 15% (since that's what an early version of the service manual stated, but then removed from later versions)? Guess what, no Nissan rep or dealer was willing or able to tell me what losing the first bar meant.

Oh, and the annual battery check on the LEAF gives the owner NO information about the state of the battery. None. It just gives the owner a statement of how well the owner is treating the battery, based on a five star rating. The i-MiEV annual check gives real information, like how many amp hours the pack can hold (correct me if I'm wrong).

I bought my i to replace my LEAF partly because the price was so low ($10k after rebates), but also because I don't trust Nissan or the LEAF instruments like I did years ago.

(stepping down from soapbox now, thank you for putting up with the rant!)
 
siai47 said:
I hate to comment about this again but there is no cooling fan in the I-miev unless you have optional equipment. Even the dealer was confused about this as I went back and complained about the lack of a fan after buying the car. Careful reviewing of his sales handbook clairified the fan sitiuation---You must have either the battery warmer or the quick charge option to get any kind of fan. I know I have read comments from Mitsubishi spokesmen talking about the two cooling systems however, they just aren't there. On my car with the battery warmer, the fan runs for a couple of seconds each time the EVSE is connected. The car without the warmer does nothing (noise wise) when you plug in the EVSE. I found the harness coming out of the top rear of the battery pack the runs to the fan. On my other car, there is a rubber plug in the same spot where the fan wiring harness would be. Also, the air the fan draws through the pack comes in from a duct located under the passenger side carpet. The duct then goes through the floor and into the battery pack. One car has all of this stuff and the other car has none of it. Even if you have the fan, it is useless for cooling the pack (if you have the warming system) and only operates during quick charging to cool the battery. After that, it doesn't do anything.
jaraczs posted photos showing the battery heating/cooling duct which evidently only exists on iMiEVs with either CHAdeMO or the battery heating system. I just checked my SE without either of those and the duct is not there :cry:

With the iMiEV, Mitsubishi is evidently more concerned about very low temperatures (hence the battery warming kicking in at -15degC) and only considers high temperatures a possible problem during the very high-current CHAdeMO charging and not during normal operation.

Wonder if anyone at Mitsubishi is re-thinking their strategy as they see us undergoing our present heat wave? :roll:
 
gmarcucio said:
Do you think the issues with Nissan Leaf's battery packs could become an issue with our MiEV's? How would Mitsubishi handle it?

http://www.mynissanleaf.com/viewtopic.php?f=4&t=13331

Didn’t I read on this forum that Nissan charged to 4.1…V and imiev charged to 3.9… V? Thus imiev doesn’t quite get a full charge and thus it should last longer.

-Barry
 
Back
Top