Data from Battery Tempurature logging

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Danl

Well-known member
Joined
Mar 6, 2016
Messages
69
Location
Vancouver, Wa
I think everyone agrees that the biggest issue with the Leaf is the battery degrading from heat. However I have not seen actual data. This has led to a lot of speculation about battery heating without having a good way to really get facts.

I found that LeafSpyPro logs lots of data and I could get that to save in files in Dropbox. So I have developed excel files that will generate charts that should be helpful.


So my first problem is how to post the Chart as a ,jpg file so that everyone can see what I am talking about. Can someone help me with instructions?

Thanks,
Dan
 
LeafMuranoDriver said:
If you're using excel, you can select the chart and copy/paste it as an image or just take a screenshot and paste it in Microsoft Paint then save as .jpg.

Hello LeafMuranoDriver,
I have it as a .jpg on my hard drive. The problem I am having is how to upload that file onto the forum.

This is image with a cut and paste...





But nothing seems to show up in the paste area

Thanks,
Dan Lander
 
Danl said:
LeafMuranoDriver said:
If you're using excel, you can select the chart and copy/paste it as an image or just take a screenshot and paste it in Microsoft Paint then save as .jpg.

Hello LeafMuranoDriver,
I have it as a .jpg on my hard drive. The problem I am having is how to upload that file onto the forum.

This is image with a cut and paste...





But nothing seems to show up in the paste area

Thanks,
Dan Lander

Look in the New Members forum. There is a topic on how to post photos. Unless you pay for the advanced membership, you can't post images directly to the forum, you have to use a link to a site that stores the images for you.
 
baustin said:
Look in the New Members forum. There is a topic on how to post photos.

Hello baustin,
Thanks for your attempt to help. I have done all that and the instructions are not making sense. I will keep trying and probably get it done at some point in the future.

$15 is not a big deal. But I feel that they are trying to extort it from me. Other Forums have this feature without charge. tTo be honest, the lack of images makes this a poorer forum.

Thanks again,
Dan
 
Danl said:
baustin said:
Look in the New Members forum. There is a topic on how to post photos.

Hello baustin,
Thanks for your attempt to help. I have done all that and the instructions are not making sense. I will keep trying and probably get it done at some point in the future.

$15 is not a big deal. But I feel that they are trying to extort it from me. Other Forums have this feature without charge. tTo be honest, the lack of images makes this a poorer forum.

Thanks again,
Dan

I have similar feelings. I think the forum software should store photos. The outside hosts for some of these photos will eventually disappear, making the posts worthless without the photos.

I've read that other members have had good results using Photobucket.
 
Ok I am trying to post this using photobucket. Lets see if it works. No Did not work that time but the third time is the charm.




So You are looking at 3 days of data.

The bottom axes is time. basically one minute per reading. You only see the day for most of it. Excel is not great at doing these labels.

The left axes is tempDegF. The right is SOC.

So I see this, the next question is of others see it.

Thanks,
Dan
 
Image is visible.

Keep in mind that battery temperature is influenced by a lot more than status of charge.

DCQC from 20 % to 90% at ambient temp in 90F range can easily raise battery temp 15F.

Rate of discharge and regeneration also have big impacts.
Running at high kW at high speed raises temp fast.

Also as with most lithium chemistry discharge to very low levels below 20 % also causes a lot of heating.

A lot of parameters to plot to see the complete story.
 
Great that baustin sees it.

Anyway, The data sometimes has holes because the Bluetooth and OBTII do not always communicate. If the holes are small with good data before and after, then I just fill it in, generally with strait lines.

I stop data at night and start again in the morning. So you see a Temperature discontinuity between days,

You can see when I drive and When I charge by looking at the SOC line Where you see SOC drop, plateau, drop, plateau.... That is driving and parking and driving and parking..... I think this is a typical pattern.

I am in an enclosed garage over night. in the morning the floor temp is generally at 66-69 degreesF. If you are in a hotter area you can do a first pass adjustment by sliding the left scale up or down to make the morning temps match what you are seeing. So as an example, if your morning ambient temp is 86-89DegF then you would expect Peaks of 103degF if you drove and charged as I did here,

I am charging with an L2 EVSE at about 4kw.

What is important in this chart is not the temperatures but rather the slope of the temperatures. The Temperatures rise while driving, but rise twice as fast during charging. My L1 EVSE is 1.4kw, so if I had used it I would expect the temp rise for driving and charging to be about the same.

The charge in the middle of 6/30/2016 was a L2 5.5kw. You see that the temp slope was much steeper. Also this was outside at about 70-75degF ambient. I would expect DCQC to be much steeper.

Thanks,
Dan
 
TimLee said:
Image is visible.

Keep in mind that battery temperature is influenced by a lot more than status of charge.

DCQC from 20 % to 90% at ambient temp in 90F range can easily raise battery temp 15F.

Rate of discharge and regeneration also have big impacts.
Running at high kW at high speed raises temp fast.

Also as with most lithium chemistry discharge to very low levels below 20 % also causes a lot of heating.

A lot of parameters to plot to see the complete story.

Hi TimLee,
The charging issue is really shown in the slope of the SOC. Again the SOC shows driving and charging with changes in slope that are easily visible. A DCQC would also show in SOC as a very steep increase in the SOC. I have not yet collected data on a DCQC. It will be interesting when I get that.

So far I do not see regen effecting me much and rate of discharge in city driving seems to be pretty consistent. I have not done much Freeway. Again it will be interesting to see how that effects the rate of discharge and temperature.

I have not done much below 20% SOC. It is good to know that I should look for added heating in that condition.

Yes, a lot of parameters, but that is why I feel that this kind of data can tell us so much.


Thanks,
Dan
 
Good data...thanks for posting!
I can see the temp rise with charging, but I can't tell if you're charging immediately (in the evening) or on a timer (in the early morning)? I know I delay charging to (try and) let the battery cool first.
 
Stanton said:
Good data...thanks for posting!
I can see the temp rise with charging, but I can't tell if you're charging immediately (in the evening) or on a timer (in the early morning)? I know I delay charging to (try and) let the battery cool first.

Look at the SOC line. Charging is when the SOC line is climbing and Driving is when the SOC line is going down. So if the SOC line goes down to a point and then starts right back up, that is charging right after driving. If the SOC line stays flat for a while before starting back up then I waited before starting the charge.

I generally charge right away because it is not to hot here. But if I saw higher temps then I would do as you do.

Thanks,
Dan
 
OK Trying it again




It was a warmer day high of 80degF low the same as before 65-68degF.

I did 3 drives with a stop in the middle of each and 3 charges. Finally the cool down data overnight.

Enjoy
Dan
 
At this point in the summer, my battery pack doesn't even get down to 85 degrees (your high) let alone anything less. I don't have a way of logging data, but I know anecdotally from checking my LeafDD.
 
Danl: These are great charts. Thanks for posting them.
I am inspired to do the same for my Soul EV. - http://www.mykiasoulev.com/forum/viewtopic.php?f=14&t=256
 
Stanton said:
At this point in the summer, my battery pack doesn't even get down to 85 degrees (your high) let alone anything less. I don't have a way of logging data, but I know anecdotally from checking my LeafDD.
Hi Stanton,
I would love to see data from hotter areas. All you need is LeafSpyPro.

Thanks,
Dan
 
JejuSoul said:
Danl: These are great charts. Thanks for posting them.
I am inspired to do the same for my Soul EV. - http://www.mykiasoulev.com/forum/viewtopic.php?f=14&t=256
Hi Jeju,
The key is the log file in LeafSpyPro putting data into Excel files in dropbox. I do not know if your software is capable of that.

Thanks,
Dan
 
Hello Everyone,
I just found an Ambent Temp logged in LeafSpyPro. I assume it is from a sensor in the Leaf.

Anyway it is very eratic. It clearly is not the outside temp reported on the dash of the car. I have calmed the data down a little by doing a 10 minute average on the data. It looks like it goes well above the real Ambent when the car is setting still and then drops back quickly when the car is driven.

Several people have reported high battery temps that cool quickly when the car is driven after a DCQC. I expect this may be part of that same issue. That is the Battery transfers heat energy to the air and thermal mass around it but the temps do not drop until the air is flushed out and flowing around that thermal mass.

Anyway does anyone know where the ambient temp sensors are on the Leaf. And if there are more than one sensor. and what sensor is being reported on LefSpyPro?

Thanks,
Dan
 
Danl said:
... Anyway does anyone know where the ambient temp sensors are on the Leaf. And if there are more than one sensor. and what sensor is being reported on LefSpyPro?

Thanks,
Dan
See http://www.mynissanleaf.com/viewtopic.php?f=44&t=14285&hilit=ambient+temperature&start=1300#p435673.

I think there is a single sensor but I don't know where it is located.

LEAF Spy Pro is recording the raw sensor value from the Canbus.

The value displayed in the eyebrow dash display has significant delays added by software.

Also note the Canbus value is invalid while the LEAF is being charged for the 2011.
It has values but is not correct.
 
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