Anyone has a i-MiEV older then mine here?

I buyed my i in march 2011. It has now two years and six months.

I think you've got the geezer title here, but at 1027 miles per month, your battery degradation curve (when it appears) should be a nice model for mine. I know that you hypermile, but how often do you put the pedal to the metal, and what's your charging regimen like?

I tend to drive hard and arrive home with more than 4 bars each day, plugging in to L2 around 7pm, which would have the car spend 8 or nine hours per day sitting at 100% SOC.
I go below two bars 2-3 times per month but can count my total turtle encounters on one hand..

A very experienced EV'er (racer and vendor for 20+ years) told me that his high-mileage 2011 LEAF battery degradation is in the bottom 2% (=good), and he attributes that to turtling the car once a month on purpose, then immediately and fully recharging in a single session. He says that we should think of Lithium batteries as a sponge. Wring it out well, and it won't stink, but let it sit dry, and it won't soak up what you want it to.

jray3 said:

I tend to drive hard and arrive home with more than 4 bars each day, plugging in to L2 around 7pm, which would have the car spend 8 or nine hours per day sitting at 100% SOC.

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Does your L2 Charger have a delay feature? I have the basic Schneider and it does have an 8 hour delay feature. I start my charging 4 hours before I need it, so that way the car is not sitting at 100% for long and my batteries are nice and warm for those cold days.

jray3 said:

I go below two bars 2-3 times per month but can count my total turtle encounters on one hand...

A very experienced EV'er (racer and vendor for 20+ years) told me that his high-mileage 2011 LEAF battery degradation is in the bottom 2% (=good), and he attributes that to turtling the car once a month on purpose, then immediately and fully recharging in a single session. He says that we should think of Lithium batteries as a sponge. Wring it out well, and it won't stink, but let it sit dry, and it won't soak up what you want it to.

Click to expand...

Flashbacks to the early days of PCs are flying through my mind right now. What is best or not for the hard drive - should we park the heads or not? This car feels more like driving a computer than it does a car. Interesting bit of information, so converse to what we've been hearing - don't go below 2 bars and don't charge above 80%. I'm following your driving pattern, I need all I got and sometimes I come in with the power gauge going spastic.

MLucas said:

Does your L2 Charger have a delay feature? I have the basic Schneider and it does have an 8 hour delay feature. I start my charging 4 hours before I need it, so that way the car is not sitting at 100% for long and my batteries are nice and warm for those cold days.

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A delay timer would be nice, but wasn't built into my SPX EVSE (now Bosch). I use the remote during winter for preheat and have also used it for delayed charging, but don't like carrying that monster fob around. The ideal timer for me would be an app that automatically brings the SOC to one setpoint immediately, and then to a second setpoint by a given time. For me, a 50% initial charge would make the car ready for emergency use. I've considered a spa timer or similar timeclock-based contactor, but haven't been convinced it's worth the trouble.

It´s becoming clear that my i-MiEV is the oldest. I am an addict hipermiler, most of my 50,000 km were made at 50 km/h. Do four charges per week up to 100%, but don´t let the car more than two hours in this situation. Normally, it never goes bellow four. I strongly advise against leaving your car at 100% for several hours, especially if the temperatures are rising. I think the most important to preserve our batteries is to keep them below 25 º C, as much time as possible. I already bought a OLB2 to better control the temperature of the battery.
Regarding the degradation curve, it had already started before I have bought it. Not long ago did 201.4 km with a single charge and i have the record of maximum RR - 174 km in august 2013. What i had lost in battery capacity, I gained in driving experience. When i receive my OLB2 i'll have more to tell. I can expect 15% of degradation, or a little more, after 2 and an half years (the summer is hot in Portugal ).

I think I saw in some thread an i-Miev (British?) with an old charging system no compatible with actual public chargers, having no data pilot wire. It has a direct cable to the plug, or similar.

But I don't remember where...

Found!

Apparently, it is a 2009 model.

But it seems the OP never again come back to the forum... :?:

http://myimiev.com/forum/viewtopic.php?p=11320

Thanks Barbagris. I´m actually the second oldest. I would like to know something about the health of that i-MiEV.

Bought our i-Miev in Feb 2011, first privately owned one in Scotland. Done 36k miles so far, not noticed any battery degradation yet.
A friend bought a Pugeiot ion 4 months ago, managed to rack up 8000 miles, just loves it!

Ok, i see mine is the third oldest. My i-MiEV battery shows some signs of degradation - some cells discharge more then others, but i only notice that at 20/15% of SoC. Sometimes he stops with 15% of SoC. My i-MiEV now charges to 96% of SoC. I presume that a new one can charge more. In practice, i have 15% less autonomy now, i think. Temperatures in Portugal are high in summer, and the temperature is the most important factor for degradation.

What is starting to appear is that battery packs "go bad" with only a cell or two that lose a lot of capacity. I wonder if Mitsubishi sometime down the road will start taking these "bad packs" and mixing them together to make good packs again for replacements. I wonder what they currently do with bad battery packs after they diagnose them.

I'm not saying your battery pack is going bad, but you are starting to see reduced range caused mainly by a few cells that were affected more by the higher temperature than the rest. I take it you use CanIon or similar, based on the fact you see SoC and have an idea of cell voltages.

Yours is older than mine, mine was a June 2012.

Yes, i use Canion.



When i took this screenshot, the car went "dead". No response to accelerator pedal. Lights and radio keep working, but the car doesn´t move. I think that's because cell 73 reached 2,75 V. When a cell reach 2,75 V it's over. Turtle only appeared 1 second before it stops. But between 96% SoC (the maximum i can get normally) and 14.5%, the car behaves like new. Because i think we can never use the last 5% of the battery, maybe my degradation can be calculated by [(100-96) + (14,5-5) =13,5%. In Portugal, Nissan Leaf from 2011 all have at least 14% of degradation. In an I-MiEV the degradation is only noted at very low values of SoC.

Not good news. The problem is not a cell, the problem is that every cell degradation goes at different rates. Replace one cell, two cells, will not improve much. Different temperatures in the pack can have a role in this heterogeneous degradation, and in a country like Portugal, with summer days whose temperatures reach 40º C, this effect is more pronounced, i think.

But i still can do 160 km in flat terrain, going at 40 km/h.

I know i´m the first showing this. I think all i-MiEV's will behave like mine in three, four, five years. So, what can i say, keep them cold.

Many of you will now be scratching your heads, but it was time to let you know about the truth of my i-MiEV (i believe some of you are following my story in http://www.nissanleafpt.com, and already knew these facts).

Please, fill free to ask me questions. I will be here ready to answer, if i'm capable to do it.

This is my i-MiEV at 74% SoC. I can easily obtain an image like this at 40% SoC. Who would say that things can turn so bad at 15%?

By the way, I take the opportunity to show this, obtained ten days ago.





175 km = 108,74 milhas

100% SoC ????? My i-MiEV only charges now to 96%, but after some hours of ending the charge and getting out the charge pistol, it changes the 96% to 100% :shock: :shock: :shock: . That's the famous malmonastic magic, did you know it? Yes, it will increase artificially your RR too.

Now you got me worried. I know mine isn't to the point of shutting down before the turtle yet (seeing how I recently drove it until the last bar disappeared right when I pulled into the driveway, and driving 3 miles on the turtle when I first got the car ), but next year, my i-MiEV will turn 2 years and I may start to see what you're seeing, although there are many on this forum ahead of me in terms of vehicle age. But then again, I don't see temperatures over 100F.

I guess we'll see how big of an effect temperature has.


To stay somewhat on topic, the oldest privately-owned i-MiEVs should be 2010 models in Japan. Any made before that were leases to utility companies.

Malm said:

When i took this screenshot, the car went "dead".

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Have you had your battery checked by the Mitsubishi dealer?
Your battery is way out of balance.
The range of your battery at 14.5% is 3.29V minus 2.755V equals 0.5345V.
Your battery voltage is only 262V.

Here's my i-MiEV battery at 11.5% with 34,888km.
The range of my battery at 11.5% is 3.69V minus 3.665V equals 0.025V.
My battery voltage is 324V.

What is the date of manufacture on the sticker in your door frame? I bought my I-Miev new in August of 2013 with 11 miles on the odometer. The sticker says it was built in Feb 2012, so I think it sat for 18 months somewhere.

Sad news, Malm...

Keep us informed.

I always thought that we could consider changing the more damaged cells. Today I have not so clear. Thanks for the graph.

Maybe worth a separate thread, something like "battery aging"

Boa Sorte!

Mine has a build date of October 2010.
I'm thinking battery might not be all healthy as I have not got more than 101 km and then the turtle came on.
It was a demonstrator, I've had it just over a week.

DaveMiller said:

What is the date of manufacture on the sticker in your door frame? I bought my I-Miev new in August of 2013 with 11 miles on the odometer. The sticker says it was built in Feb 2012, so I think it sat for 18 months somewhere.

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I can't find that sticker. Maybe it hasn´t it.