Trip round Neusiedlersee, Burgenland, Austria

[me68]

Hello!

"As every year:" Last saturday i made a trip round Neusiedlersee, Burgenland, Austria, as already 2015 and 2014.

The battery was slightly coulder this year (2016: 17,4°C -> 23,6°C, 2015: 23,4°C -> 25,8°C, 2014: 19,1°C -> 21,3°C).

I used the battery from 100% to 2% SoC with 14.749Wh - 658Wh = 14.091Wh. There was no buffer at all this time. On reaching 2% SoC, respectively near 1,5% SoC the car coast to a stop in 400m distance to my sweet home. Cell 57 reaches 2,75V, so BMS do a shutdown of the battery. In 2015 the whole amount of energy for use was 14.885 Wh, in 2014 this was 14.865Wh. This was the first time without buffer from the BMS. So battery degration in future will result in lower amount of energy usable. Till now this amout was always the same, but the final discharging voltage of the individual cells drop down.

caniOn ScreenShots:

Cell voltages at departure:

Cell temps at departure:

Charging from wall was 16.500Wh for this trip (via Ferraris-counter).


Martin

 

[PV1]

Nice to see full discharge stats.

So, it appears one, going on two or three, cells are degrading a bit faster, as shown by the lower voltage. So, in a few years, changing out these few cells would net an extra km or two, what ever 2% SoC will deliver.

Are the cells with lower voltages physically close? It appears some of the cells from #57 to #72 have less capacity than the rest of the pack. I wonder if this is the luck of the draw when packs are assembled, or if these are interior cells that are more affected by elevated temperatures (even if the BMU doesn't report higher temperature, these cells could be warmer if they are surrounded by other cells, and/or the modules are laying on their side).

 

[kiev]

Excellent trip report as usual--did you walk or push, how did you get the final 400m to home?

 

[JoeS]

Martin, thank you for posting. I see that this year your 94Wh/km beat last year's 100Wh/km for the same trip, and yet you 'ran out of juice' this year. Nice to see your replacement cell holding up!

 

[blackheart]

What have people seen as a 'high' battery temperature? We have been having abnormally high temps for April. Yesterday was near 90°F. At the end of my trip home and errands, after about 25 miles, the battery temp was 81°F. I see the battery temps in Martin's screen pics as only 24°C, which would be around 75°F.
At what temp should I be concerned?
Thanks

 

[PV1]

I get nervous when the pack gets above 30 C (86 F). This is the point where the car activates AC when quick charging (otherwise only the fan runs). To compensate, I either manually force cool air into the pack, or time my charging so the car spends most of the night idle, allowing the pack to cool down.

The battery mainly is affected by usage and average temperature. So, if it is 90F through the day but only 60F at night, then your pack would stay cooler than you'd think. 81 F isn't too bad and is about normal for the conditions. What you might want to do is start charging the car around 8 PM or so (or set a delay for 2 hours if you get home later). This way, the car will finish around midnight on level 2, and the pack will be able to cool down through the night. Try not to use level 1, as the lengthened charge time actually keeps the battery warmer, but this is good for the winter.

 

[blackheart]

The battery mainly is affected by usage and average temperature. So, if it is 90F through the day but only 60F at night, then your pack would stay cooler than you'd think. 81 F isn't too bad and is about normal for the conditions. What you might want to do is start charging the car around 8 PM or so (or set a delay for 2 hours if you get home later). This way, the car will finish around midnight on level 2, and the pack will be able to cool down through the night. Try not to use level 1, as the lengthened charge time actually keeps the battery warmer, but this is good for the winter.

I am wiring up an external plug for Level 2 this week. This weekend, I will have the Mitsu dealer program the replacement remote that Carmax got for me so I can program it to start in the middle of the night or when ever. Right now, all I have is Level 1. But it is the EVSEupgrade. It is supposed to be doing 12 amps, but with Canion I see that it is pulling about 11 amps at 110V. Shaves off a little time...

 

[me68]

Hello!

Excellent trip report as usual--did you walk or push, how did you get the final 400m to home?

My wife towed me home with our second car.

I get nervous when the pack gets above 30 C (86 F).

Round cell 23 replacement last year i also talked with an mitsubishi technician from Vienna regarding cause of failure. I suspected "high temperature" 2 weeks before i see cell 23 did not fully charge anymore. There were temps with round 46°C highest. He told me temps with 60°C up are a problem for the cells.

Nice to see your replacement cell holding up!

Yes! - it's the strongest cell in the pack now


Martin

 

[Malm]

Excellent, Martin.
As I have been saying for the last 3 years, I-MiEV doesn't recalculate it's capacity frequently. So, each one of the 16 bars values approximately the same energy for 2 or 3 years. But the battery capacity is dropping, so there will be one day that the car will stop before reaching 0,0% SoC. That now happened to Martin. If it doesn´t recalibrate its capacity in the next two years, then it can stop without even going to turtle, two years in the future.

I believe this year is the first that Martin has a real loss in range because of loss in capacity. In the first 3 years Martin's car maintained exactly the same range, but SoC at 0,0% was at lower voltages, month by month. So Martin's car loses only 2% of range in 3 years (but something like 15% in battery capacity - I predict 41/42 Ah of battery current capacity).

 

[Malm]

I believe cells 57 and 65 are located side by side, in an internal position.

 

[kiev]

i was thinking that the dealer had to run the automatic capacity check using the MUT--the procedure is posted on my blog site LINKED HERE