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Traction battery going bad or something else?

Posted: Tue Nov 28, 2017 8:26 am
by RobbW
I have a 2012 iMiEV SE. I bought it in July 2013, and it currently has 43,000 miles on it. Up until this past Sunday, it has charged fully (16 out of 16 kWh bars and around 70 miles +/- of RR) every time I have allowed it to charge until full. The Friday after Thanksgiving, we went on a mini vacation out of state for the weekend. We drove our Pacifica Hybrid and left my Meepster at home unplugged. Sunday night when we got home, I plugged the Meeptser into the Leviton L2 EVSE in our garage to make sure it was fully charged and ready for my work commute on Monday. The next morning, I came out to drive to work and found that the Meepster had only charged to 75% (only 12 out of 16 kWh bars and 40 miles RR). Confused as to how this happened, I drove to work and plugged it into the Chargepoint L2 EVSE at work.

During the workday, I received the automated text message from Chargepoint letting me know that my vehicle had completed charging. At the end of the day, I went out to my car to find it once again had only charged 75% (12 out of 16 kWh bars and 40 miles RR). I drove home with the heat on and got home with about 4 kWh bars remaining. I plugged in at home and let it start charging immediately instead of putting it on the schedule.

A couple hours later, I checked in on the Meepster and saw that the charging light on the EVSE was green indicating my car was fully charged. That was odd because it should have taken much longer than that to fully charge. I pressed the "Send" on the remote to check the charge status, and it showed only 2 out of 3 bars. I unplugged my Meepster and plugged it back in to see if it would start charging the rest of the way. It initially made the loud click and the fan noise usually associated with charging, but the EVSE then clicked off after about 10 seconds. I tried unplugging and replugging a couple more times to no avail. At this point, I left it alone assuming I was going to have to call the dealership in the morning to make an appointment.

Just before going to bed, I took my keys out to the Meepster and turned the ignition to the "On" position so I could check the miles on the odometer because I wanted to include that info in this post. After getting the miles and turning the car back off, I decided to try unplugging/replugging one more time just for the heck of it. This time, the charging light stayed on and the car made all the different noises usually associated with charging. The EVSE kept the charging status light on for the entire 5 minutes I was standing there watching it. I assumed that whatever issue my Meepster had been having with its charging system must have cleared up by me turning the car on while it was plugged in. I went to bed hopeful that I would have a fully charged iMiEV in the morning.

This morning, I went to go to work and found that my Meepster, once again, was only showing 12 out of 16 kWh bars charged and only 40 miles of RR. Grrrrrrr!!!!!

I am now at work and will be calling the dealership to make an appointment to bring my car in. I figured I would post here first to see if anyone has any suggestions or recommendations on things I could checked to hopefully clear up this problem. Or is this definitely something only the service department at the dealership is going to be able to fix? This certainly does not seem like the normal and expected battery capacity degradation that is mentioned and warned about in the owners manual. If the Meepster still fully charged to 16 kWh bars but was steadily getting fewer miles on a full charge, then I would assume it was the expected battery degradation. However, this situation is my car suddenly not even fully charging to the 16 kWh mark! I assume this must be indicative of bad cells in the traction battery, right? Or is there something else that might cause this? It's definitely not my home EVSE as this is happening on my work's EVSE, too.

Re: Traction battery going bad or something else?

Posted: Tue Nov 28, 2017 8:48 am
by RobbW
Okay, so I found the thread below from another owner in Australia who sounds like he experienced the exact same issue I am having. I didn't see that thread until after I posted. I'm sorry for posting a new thread on the same topic, but I was just trying to quickly get my issued posted (and hopefully some responses from you great folks) before I called the dealership to make an appointment. I've only read through page 1 of 6 so far but will now continue reading the rest of the thread to see if there was any satisfactory remediation. Thanks!

Re: Traction battery going bad or something else?

Posted: Tue Nov 28, 2017 8:57 am
by kiev
Sounds like you are having the same issue that i have right now--a weak cell in the battery pack. See this


Re: Traction battery going bad or something else?

Posted: Tue Nov 28, 2017 11:20 am
by iDriver
Greetings. I would recommend taking it to the dealership and getting the battery replaced under warranty right away. I say that, because that's what I had to do! This was a little more than a year ago. The car had 50k+ miles on it, and was purchased in Jan of 2012. I'm not upset about this, because that's what a warranty is for, and I knew the risks with being an early adopter.

Yup, new pack for me. I had 2 Cells that would drop out and cause the Turtle to pop out whenever the car was under load. First started having the issues via Up Hill climbs. It took the dealership more than a month to actually figure out what was going on, but they eventually did. (I actually showed them the CanION app and road with a tech in the car so he could see the data. They were very impressed!) I learned my lesson on that one and now i take the car to another dealership, they know how to work on the i-MiEV and all is good.

Re: Traction battery going bad or something else?

Posted: Tue Nov 28, 2017 1:29 pm
by RobbW
I have an appointment to drop the car off at the dealership tonight. They will have it all day tomorrow to do whatever inspections and testing is required.

For those who had similar issues and took your iMiEV in for warranty repairs, did the dealership give you any hassles about not following any sort of maintenance program in order to keep the vehicle under warranty? The dealership I bought my Meepster at did not give me any sort of warranty-required maintenance program I had to follow at the time I bought my car. Nor did they mention any required maintenance in the several times I have taken it back to the dealership for recalls or other miscellaneous issues. I am concerned, but only slightly, that they may try to balk at replacing the battery pack under warranty and give me some excuse about not following the Mitsubishi required maintenance program (whatever that program may be, if there is such a thing for the iMiEV).

Re: Traction battery going bad or something else?

Posted: Tue Dec 05, 2017 11:13 am
by RobbW

Dropped my Meepster off at Bigger's Mitsubishi in Elgin, IL last Tuesday night, Nov. 28. Didn't hear from them until late afternoon on Thursday. The verified that they have duplicated the problem I am having with charging up to only 12 out of 16 bars. They said they had spent the last two days fully depleting the battery and then fully recharging with the same results.

The service manager said he was working with Tech Engineers from Mitsubishi to identify the problem and the est solution. He said the tech engineers sent him a huge questionnaire that he had to ask me so they could figure out what they were going to do. Took about 10 minutes to get through the questionnaire. It was all questions about my driving and charging habits. I'm sure they're just trying to CYA and see if there is a way to get out of having to pay for a full warranty replacement.

Anyway, they sent my answers off to Mitsu, and I didn't hear anything more until yesterday afternoon. I called the service manager because I wanted an update and needed to find out how long it's going to take because I needed to make alternative transportation arrangements. Luckily, they told me to come in that evening, and they would give me a loaner car.

The service manager explained that they had run several more diagnostic tests and determined that the main battery pack has a bad cell that is under-performing compared to all the other cells. They were planning to hook my Meepster up that night to perform a "smoothing" operation that may or may not help bring the bad cell back into proper specs. He told me he is still waiting to hear a final determination from the tech engineers at Mitsu as to whether it's going to require a full battery replacement. During both times I spoke with him on the phone, he kept mentioning just how expensive the main battery is if it needs to be replaced. It was almost like he was subconsciously trying to make me feel guilty about it. I assumed that any warranty repairs are fully reimbursed to the dealership by Mitsu, but is that not the case? Is the dealership also on the hook for a portion of the warranty replacement?

Anyway, the service manager explained that he has to wait for final word from the tech engineers. He can't even go ahead and order the new battery even if he wanted to. In fact, he explained that he has no control over that process whatsoever. That if a battery replacement is authorized, Mitsu will just ship it right out to him without him even having to order it or anything. They will also have to send out all the tools and specialized equipment for lifting and installing the battery pack.

That's all I know for now. I'll update again when I hear anything more. In the meantime, I'm driving around in the Outlander Sport (ICE) they're letting me use. This is a really weird feeling driving a fully-ICE vehicle again. Now that our family is an all EV/PHEV family, I am noticing all the peculiarities of ICE cars that I never noticed before!

Re: Traction battery going bad or something else?

Posted: Tue Dec 05, 2017 12:18 pm
by JoeS
RobbW, thank you for the update.

So far, Mitsubishi has been very good about replacing battery packs which exhibit the problem you're experiencing.

To me it's unclear whether that single cell problem is a defective cell (most probably) or the BMS as it applies to that cell.

For Mitsu, it is an expensive process as they ship the replacement pack to the dealership with all the special equipment to remove/replace the pack.

We have had at least one member successfully replace a defective cell in his pack - Martin (me68), developer of CaniOn. detailed in this thread:

Replacing an individual cell with one of similar capacity to the rest of the pack is another variable - to me, off the top of my head I don't see why a 'better' cell would necessarily be a bad thing, recognizing it is a series string of 88 cells.

This is quite a dilemma for Mitsubishi, as, although the cell replacement itself is fairly straightforward, the technician education and OSHA constraints when working with high voltage are formidable enough that only pack replacement at dealerships is presently viable.

RobbW, based on my and others' past experience, Mitsubishi will take care of you. In the mentime, have fun driving your poison-gas-spewing ICE loaner.

Re: Traction battery going bad or something else?

Posted: Tue Dec 05, 2017 7:12 pm
by kiev
i would be very interested to hear the results of the "voltage smoothing". i have a low cell and went to the dealer to ask if they would perform this on my car, but they said the discharge and charging procedure would have to be done a couple of times and then they talk to Mitsubishi and do what they say. i've already charged numerous times and i have cell data from two different sources that show which cell is low--i'm sure they could verify that if they knew how to command the MUT to read the cells.

In the meantime i bought a copy of the MUT software and have a laptop on which to run it. The missing link to having my own MUT is the VCI box--vehicle communication interface, which connects to the OBDII port on one cable and to the PC over USB. There are many of these found on ebay but they don't seem to really have the full programming capablilty. The i909 from icarsoft will do everything except programming also, and it is much less expensive--but i don't need another data-reader, i want all the functions so i can do cell smoothing on my own time...

Re: Traction battery going bad or something else?

Posted: Wed Dec 06, 2017 7:11 am
by RobbW
The service manager at Bigger’s Mitsubishi just called me. Mitsu is going to go ahead and replace the main drive battery. He said they have the battery packs in stock at their facility in Atlanta. Normally, it would only take a couple days to get them delivered. However, the issue is the lifts and special equipment that are required to replace the battery. He said that Mitsu USA only has 5 sets of the specialized equipment in the entire country, and right now, they are all out to other service departments. So, it may take a week or a week and a half to get the equipment. He will update me once they get the tools and the battery.

So, bad news is that it’s going to be a couple weeks before I get my Meepster back. Good news is that I'm getting a brand new battery pack! So, it’s basically like getting a reset on the life of the power train of the car!

Unfortunately, he never mentioned anything about the results of the smoothing operation. So, I cannot provide any further details on that. Suffice it to say, the results were not positive.

Re: Traction battery going bad or something else?

Posted: Wed Dec 06, 2017 7:25 am
by RobbW
Anyone know if replacing the main battery pack resets the warranty on the battery? Or do you only get the remaining life of the warranty?