The 40KWH Battery Topic

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
danrjones said:
Where are the temp sensors on the battery?

Last night I went to bed the temps were 97.7 max and 96.2 min, not a big spread.

This am the temps were 87.4 and 80.6. Pretty big spread?

Not a big spread at all. Jump in the car and drive it. The spread grows considerably.
 
danrjones said:
I have, usually (for me) its only a couple degrees apart. Anyway, still makes me wonder what is what for the sensors.

It may just be an illustration of how heat moves through the pack, or it may be an artifact of the sensor location, or even of how they are manufactured...
 
LeftieBiker said:
danrjones said:
I have, usually (for me) its only a couple degrees apart. Anyway, still makes me wonder what is what for the sensors.

It may just be an illustration of how heat moves through the pack, or it may be an artifact of the sensor location, or even of how they are manufactured...

At lunch the spread was back to about 2 deg F, about 82.8 and 80.8. As you say, maybe the spread is caused by the lag as the outside (or some part of the battery) cooled at night faster than the inside. For the first time in about 4 months we got down to a bone chilling 60 F last night.
 
I finally got a chance to check out the range on the new Leaf (2018 SV) as I had to drive 65 miles each way to an event yesterday. This is the first time, in 6 months of having the car, that I have really needed to push the range at all so I was looking forward to the results...

I charged to 100% the night before and I arrived at home with 129.5 miles traveled and 14% remaining on the SOC display.

90% of the trip was interstate traveling between 65 - 75 mph the rest was surface streets with 45mph speed limits and a short period of 25mph near both destinations. I only used A/C on the return leg in the afternoon.

I was pretty impressed, the car might actually get close to the 150 miles of range at what I consider to be normal highway speeds (~70mph).
 
LeftieBiker said:
danrjones said:
I have, usually (for me) its only a couple degrees apart. Anyway, still makes me wonder what is what for the sensors.

It may just be an illustration of how heat moves through the pack, or it may be an artifact of the sensor location, or even of how they are manufactured...

I think its sensor location. I let mine sit more than 12 hours and the temps begin to merge occasionally within one degree. But get out and drive it and one will quickly diverge from the pack when the pack heats up getting to as much as 20º difference with 10+ being typical. Made me think there was some sort of circulation causing this, speaking of which.

A bombshell comment made by a VERY reputable person from Nissan stating 62 kwh packs now have circulation fan. Still waiting on more details on that.
 
DaveinOlyWA said:
LeftieBiker said:
danrjones said:
I have, usually (for me) its only a couple degrees apart. Anyway, still makes me wonder what is what for the sensors.

It may just be an illustration of how heat moves through the pack, or it may be an artifact of the sensor location, or even of how they are manufactured...

I think its sensor location. I let mine sit more than 12 hours and the temps begin to merge occasionally within one degree. But get out and drive it and one will quickly diverge from the pack when the pack heats up getting to as much as 20º difference with 10+ being typical. Made me think there was some sort of circulation causing this, speaking of which.

A bombshell comment made by a VERY reputable person from Nissan stating 62 kwh packs now have circulation fan. Still waiting on more details on that.


Maybe a dumb question, but could one of the three temp sensors (I only see three), could it be on the motor?
 
DaveinOlyWA said:
A bombshell comment made by a VERY reputable person from Nissan stating 62 kwh packs now have circulation fan. Still waiting on more details on that.

I saw that post, but I don't really believe it. It is true that I see my Plus battery pack heat up much less than my 30 or 40kWh packs did, even with multiple long fast charging sessions, but I have mostly attributed that to the lower C rate. On my last long trip, our second charge lasted 55 minutes and we gained over 40kWh to a 94% SoC, which suggests that we were getting close to the full 44kW rate of the charger up to ~90% SoC. Even then, we only had 8 temperature bars. I'm afraid I neglected to get a LeafSpy reading at that point. Still, I didn't hear any sort of fan noise coming from the car, so if there is a fan, I can't imagine it's doing much.
 
Astros said:
DaveinOlyWA said:
A bombshell comment made by a VERY reputable person from Nissan stating 62 kwh packs now have circulation fan. Still waiting on more details on that.

I saw that post, but I don't really believe it. It is true that I see my Plus battery pack heat up much less than my 30 or 40kWh packs did, even with multiple long fast charging sessions, but I have mostly attributed that to the lower C rate. On my last long trip, our second charge lasted 55 minutes and we gained over 40kWh to a 94% SoC, which suggests that we were getting close to the full 44kW rate of the charger up to ~90% SoC. Even then, we only had 8 temperature bars. I'm afraid I neglected to get a LeafSpy reading at that point. Still, I didn't hear any sort of fan noise coming from the car, so if there is a fan, I can't imagine it's doing much.

But there is two ways to read that - that Leaf plus's have a fan, or that "now" they have a fan, meaning some plus's did not and new ones do?
 
LeftieBiker said:
Maybe a dumb question, but could one of the three temp sensors (I only see three), could it be on the motor?


Most things are possible, but I doubt that this one is true.

Yes, but some part of the battery (or whatever is monitored) heats up much faster than the rest.

I'm not sure if leafspy arranges so Temp1 is always the hottest, or if temp1 is always sensor 1?
in my case Temp1 (left reading in leafspy) seems to always be the hottest.
 
danrjones said:
But there is two ways to read that - that Leaf plus's have a fan, or that "now" they have a fan, meaning some plus's did not and new ones do?

I guess that's possible, but this rumor has existed for a long time, and was just recently repeated by someone who ought to know more than us. Sometimes it seems the people closest to Nissan have drunk too much off the Kool-Aid, and stubbornly believe Nissan PR over anything else. Look at the reactions by Nissan insiders to Rapidgate.

In any case, I can't see them making a major change like this only 6 months after the Leaf Plus went on sale.
 
Astros said:
I saw that post, but I don't really believe it. It is true that I see my Plus battery pack heat up much less than my 30 or 40kWh packs did, even with multiple long fast charging sessions, but I have mostly attributed that to the lower C rate. On my last long trip, our second charge lasted 55 minutes and we gained over 40kWh to a 94% SoC, which suggests that we were getting close to the full 44kW rate of the charger up to ~90% SoC. Even then, we only had 8 temperature bars. I'm afraid I neglected to get a LeafSpy reading at that point. Still, I didn't hear any sort of fan noise coming from the car, so if there is a fan, I can't imagine it's doing much.
Agreed that a lack of fan noise says a lot. I have heard Teslas at Superchargers that sound like little airplanes with propellers.
 
danrjones said:
Yes, but some part of the battery (or whatever is monitored) heats up much faster than the rest.
No doubt. And the cells towards the perimeter cool off first. Such is the life of a passive cooling design
 
Astros said:
DaveinOlyWA said:
A bombshell comment made by a VERY reputable person from Nissan stating 62 kwh packs now have circulation fan. Still waiting on more details on that.

I saw that post, but I don't really believe it. It is true that I see my Plus battery pack heat up much less than my 30 or 40kWh packs did, even with multiple long fast charging sessions, but I have mostly attributed that to the lower C rate. On my last long trip, our second charge lasted 55 minutes and we gained over 40kWh to a 94% SoC, which suggests that we were getting close to the full 44kW rate of the charger up to ~90% SoC. Even then, we only had 8 temperature bars. I'm afraid I neglected to get a LeafSpy reading at that point. Still, I didn't hear any sort of fan noise coming from the car, so if there is a fan, I can't imagine it's doing much.

I only consider it newsworthy because of the source who I trust A LOT. Remember he just returned from the Corporate awards ceremony where exposure to the upper echelons of LEAF design is not only possible but expected so the timing of his reveal is not a surprise.

As far as testing heat dissipation; charging to high SOC is not the way to do it. The ramp down is designed to mitigate the heat issues. If you want to do a real test; Only charge to the knee where the current starts to drop. Do that repeatedly and you should gain much more heat over the same distance traveled (and spend a lot less time charging)

FYI; the full rate on "most" chargers around here at 90% SOC would be higher than 44 KW. That is only 366 volts. Do you have a charge curve you can post?
 
danrjones said:
LeftieBiker said:
Maybe a dumb question, but could one of the three temp sensors (I only see three), could it be on the motor?


Most things are possible, but I doubt that this one is true.

Yes, but some part of the battery (or whatever is monitored) heats up much faster than the rest.

I'm not sure if leafspy arranges so Temp1 is always the hottest, or if temp1 is always sensor 1?
in my case Temp1 (left reading in leafspy) seems to always be the hottest.

In settings you can change order you see temp sensors so yeah, you can arrange them from high, average and low. FYI; even if using sensors, the last one will still be lower than the first two but at least you will see situations where the 2nd one is higher than the first one. I tried both and the info varies so little that its an "either or" preference.
 
Thanks

There is definitely some thermal mass there. We were 56 this morning and my temps were 78 and 72, max and min. I would "assume" the bigger pack on the plus would have an even bigger thermal mass, but if its packaged into the same space, maybe not. Is it physically bigger?
 
frontrangeleaf said:
Not bigger but several hundred pounds heavier. Definitely more thermal mass. More mass period. Same surface area.

Correct, which implies a longer thermal time constant to heat/cool.
 
Back
Top