Battery Failure?

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tonymil

Well-known member
Joined
Apr 16, 2012
Messages
274
Location
Latham, NY
So just a few weeks after my first service I'm having charging problems. Starting last Sunday my car only charges to 15 bars. I've spent this past week trying different things to see if I can figure out what's going on. At first I thought it might by my Eaton charger because this happened right after a power outage - the car was not plugged in when we lost/restored power. So I tried charging with the L1 charger and the same thing is happening. I have sat in the car and watched it during the last hour of charge and it actually shows 16 bars for a while but then when the charging stops it's down to 15 bars. I am bringing my car to the dealer on Monday and they will calibrate the battery again.

The only other recent "event" I had was a minor fender-bender about 2 1/2 weeks ago. But all that did was push in my front bumper and I brought it to someone who popped it back out. So because of the minor damage and because it was charging fine for over a week after that I can't imagine that the two are related.

As you can imagine this is very unsettling. I'm hoping its just a computer issue and not a battery problem. As soon as I have info from the dealer I'll post it here.

Tony
 
tonymil said:
So just a few weeks after my first service I'm having charging problems. Starting last Sunday my car only charges to 15 bars. I've spent this past week trying different things to see if I can figure out what's going on. ?.....I am bringing my car to the dealer on Monday .....

As you can imagine this is very unsettling. I'm hoping its just a computer issue and not a battery problem. As soon as I have info from the dealer I'll post it here.

Tony

I'll repeat the suggestion posted earlier: Have you tried running the charge level down to 2 bars or less followed by a full charge? That procedure is supposed to calibrate the charge level gauge.

An also... Maybe you SHOULd hope it IS the battery ... As in that case (assuming you're not over 8 years or 100,000 mile) you'd likely be given a brand new battery under warranty.
 
I thought I posted a reply but I don't see it. My range is definitely down. As for going down to 2 bars, I actually went turtle mode the night I lost power. I drove about a mile with zero range and the turtle showing and when I got home the power was already out so my car sat with very little power from about 8 pm to 12 am. I plugged it in as soon as the power came back. That was a Wednesday and I first noticed the charging problem the following Sunday. I'm taking the advice here and drove my car down to 9 miles rr and it's charging now. I'll update tomorrow.
 
tonymil, that's not good news :(

I'd be inclined to go to the dealer and have them perform a battery check to see if all the cells have uniformly lost capacity or if perhaps only a number of cells have problems (more likely).

In the past, I've murdered many lead-acid battery packs by not only discharging them heavily but then failing to charge them back up immediately. Need to read up on Lithiums to determine their failure mechanisms...

In the meantime, this is a warning to all of us NOT to heavily discharge the pack ... there are only so many safeguards a manufacturer can put into place, the conflict being allowing us to still be able to drive the car when almost empty vs. shutting it down earlier. If you get to zero bars, simply STOP and plug her in, that's one of the uses for our Mitsu L1 EVSE.
 
I dropped the car off at the dealer this morning. I fully charged the car overnight and got 15 bars and 73 miles RR. The service tech asked me to bring the car in with very little charge left so I went on a 55 mile joyride before bringing it in. I should hear from them by tomorrow.
 
tonymil, keeping our fingers crossed, and thank you for the update. 15 bars and 73 miles, not all that bad. Yours is the first instance that I know of that told us that a reduced-capacity indication is shown by 15 (or 14) bars when the charging routine stops.

When one of my other EV LiFePO4 packs became badly unbalanced due to a heavy discharge, it took a few longer balancing charges to bring everything back and it has been fine ever since. Inasmuch as our iMiEV balancing only takes about an hour and seems to stop well before zero current, maybe that's all it will take (?).

Looking forward to the results of the Mitsubishi analysis, and thanks again for sharing.
 
So I got a call from the tech guy today. He said there is a bad cell in the battery and because of it the battery is not properly balancing. He said Mitsu is also concerned because the car should have given me a warning that the cells were not balancing - some light was supposed to come on. He asked me some questions about my driving habits and said he'd be performing more tests today and would call again tomorrow. He didn't say whether the car going into turtle mode and then sitting with a low charge for 4 hours may have caused/contributed to the problem. Stay tuned....

Tony

PS. I'm very bummed by this. I'm sure the battery will be fixed, it's under warranty after all. But it's disappointing to have this happen especially since my car was driving perfectly before this happened. Plus I've gone two days without my car and I miss it. :cry:
 
I spoke with the tech guy at my dealer today. Mitsubishi corporate has decided to give me a new battery because two cells in my battery are defective. I was told by the tech guy that my situation of driving a mile with zero range and then not being able to charge for 4 hours did not cause the defect, he said the car and battery are made to tolerate that situation. He didn't say this but my guess is that even though that event didn't cause the defects in the cells, it exposed them. It just seems too coincidental that I have that problem on a Wednesday-Thursday and the following Sunday the car won't fully charge.

So I also was told that a battery will be built specifically for my car and that it should take two weeks to arrive. In the meantime I'll be driving my Mitsu with its diminished range. Kudos to Mitsu for a hassle-free honoring of the battery warranty and for not trying to just replace the defective cells.
 
That sounds like the best resolution to the problem that you could have asked for - you get a whole new battery out of it. Good to hear that Mitsubishi is so good about dealing with battery issues.
I had talked recently to a Mitsubishi Canada EV distribution specialist, and was told that if there is a defective battery that needs to be replaced, they actually get a whole new i-MiEV shipped to the dealer doing the work, who then swaps the battery with the defective one, and ships the whole car back to Japan. This is due to some rules about not being able to ship the Li-Ion battery packs on their own because they are dangerous cargo, and apparently the car serves as 'proper packaging'.
 
HParkEV said:
I had talked recently to a Mitsubishi Canada EV distribution specialist, and was told that if there is a defective battery that needs to be replaced, they actually get a whole new i-MiEV shipped to the dealer doing the work, who then swaps the battery with the defective one, and ships the whole car back to Japan. This is due to some rules about not being able to ship the Li-Ion battery packs on their own because they are dangerous cargo, and apparently the car serves as 'proper packaging'.
Oh WOW! My car, the reusable container. :lol: That's in the running for the funniest thing I've heard this month.

But seriously . . . On the one hand, yeah, adventures in regulation. But on the other, they probably have a point - an open battery pack could get into all kinds of mischief. For their part, Mitsubishi probably finds it much cheaper to designate a few cars (which after all DO have all kinds of safety features to protect the batteries in a collision and reduce risks to passengers and emergency responders) to serve as carriers than to design and manufacture a custom "carrier system" to properly secure a battery pack given how infrequently this should be needed (we hope).

Even so, this would never have occurred to me - it just strikes me funny :)
 
tonymil, I'm delighted Mitsubishi is standing by its product! A battery problem is such a rare occurrence (to date, yours is only the second NA battery issue I know of), that there's good reason to be optimistic for the long term. I certainly haven't noted any degradation after almost 16,000 miles (25000km).

inasmuch as Mitsubishi has already committed to replacing your traction battery pack, could you perhaps see if you're able to revive your defective cells by repeatedly fully charging the pack (after some discharge) all the way through its balancing cycle until it shuts itself off and seeing if the fuel gauge gets up to 16 bars? Just trying to start a body of knowledge for the future…
 
Tony:

I second Joe's comment; recommend a full charge when you are down to six to eight bars remaining. With about 10 days until new pack arrives, this should give you a chance to do this process a few times. Bill.
 
JoeS said:
inasmuch as Mitsubishi has already committed to replacing your traction battery pack, could you perhaps see if you're able to revive your defective cells by repeatedly fully charging the pack (after some discharge) all the way through its balancing cycle until it shuts itself off and seeing if the fuel gauge gets up to 16 bars? Just trying to start a body of knowledge for the future…

I'm trying to drive/charge the car as I normally would, but with greatly reduced range. I woke up this morning to a "fully charged" car with 15 bars and 62 miles rr. So it seems the battery's ability to hold a charge is going backward. I'll post updates every once in a while to let folks know how it's going.
 
So, this may be a wider problem. I can't imagine what this recall is going to cost Mitsubishi.

http://www.consumeraffairs.com/news/mitsubishi-recalls-batteries-used-in-2012-mitsubishi-i-miev-vehicles-061813.html
 
tonymil said:
So, this may be a wider problem. I can't imagine what this recall is going to cost Mitsubishi.

http://www.consumeraffairs.com/news/mitsubishi-recalls-batteries-used-in-2012-mitsubishi-i-miev-vehicles-061813.html

I think this should not be your problem. Only a few units affected:

The batteries were manufactured December 18, 2012, through December 21, 2012.

We discuss this here:

http://myimiev.com/forum/viewtopic.php?f=2&t=1498

http://myimiev.com/forum/viewtopic.php?f=2&t=1418

and I think your unit is older than that.

Keep us informed!
 
Thanks for that follow-up, Barbagris. I didn't read the article closely enough. That's what I get for surfing the web while watching the NBA playoffs. :)

But as a follow-up to my own situation, my car seems to have settled at 13 bars on a full charge. I'm getting an RR of about 62 miles but mainly because I'm being much more cautious about staying in the eco range. Also, the dealer told me the replacement battery would be here in two weeks but I spoke with Mitsu corporate in Calif. and was told 40 to 60 days.
 
Any updates on the replacement battery pack ?

Mitsi must have great confidence in their BMS to send an i with a cell fault back out on the road.
There is a risk of somewhere between inconvenience and gross failure if there is a known cell fault.
...unless perhaps there is a BMS shunt equalisation fault (open circuit) that allows one (or more) cell voltage to go high (4.2V) and trip premature end of charge. i.e. a fault that is still backed up by a seconds shutdown feature.

The battery SOC gauge is a very accurate kWh counter. If it says you only put 14kWh in then that is all you can get out.
I read about calibration, however tonymil's experience shows that what actually happens with 'aging' will be that a full charge just won't get to the top of the gauge anymore ? i.e. meter still reads 16kWh full scale.
Or is calibration in this case mislead by a cell fault ? Well no, it just tells kWh as usual.

Another test would be to charge at lowest possible charge current. Use 100V level 1. (I would use my charge-amps 230V J1772 set to 6A for instance). The lower the charging current the more chance of battery equalising. Compare with DC fast charge that has to back out at 80% SOC as there is risk of imbalance.

But still on the first point... if a cell is the fault then the BMS overcharge/overdischarge and temperature monitoring should shut things down. I'd have thought that if a cell was faulty then it would be potentially risky. Mitsi obviously has confidence in their battery pack. I guess we should fell re-assured.
 
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