Rapidgate fixed in Europe

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I checked my BMS version, and has the same as the guy has in the video (he has 5SH3C, I have 5SH2C, mine is without battery heater, C is for the 3rd revision of the BMS, 5SH means 40kWh battery pack). However I never needed more DCQC than 1 in a day, so I could not test it, however my Leaf tapers down charging rate much earlier, than seen in older cars, before it was above 60%, when it started to taper down, mine starts with it around 50%, so 10% earlier.

I have a Leaf manufactured end of August or latest start of September.
 
kovadam said:
I checked my BMS version, and has the same as the guy has in the video (he has 5SH3C, I have 5SH2C, mine is without battery heater, C is for the 3rd revision of the BMS, 5SH means 40kWh battery pack). However I never needed more DCQC than 1 in a day, so I could not test it, however my Leaf tapers down charging rate much earlier, than seen in older cars, before it was above 60%, when it started to taper down, mine starts with it around 50%, so 10% earlier.

I have a Leaf manufactured end of August or latest start of September.

In colder weather the knee (or "taper" in your words) happens sooner if batteries are cold during start of charge

https://daveinolywa.blogspot.com/2018/12/cold-verses-leaf.html
 
Björn verified that newer Leafs have different tapering:
https://www.youtube.com/watch?v=J92fS73qw8c

With this kind of allowance new Leaf with 60kWh pack will be fine
with refrigerant-air cooling system. It will extract heat at 2-3kW rate.
Though do not expect any faster charging than 70-80kW - fine for a cheap car :)
 
arnis said:
Björn verified that newer Leafs have different tapering:
https://www.youtube.com/watch?v=J92fS73qw8c

With this kind of allowance new Leaf with 60kWh pack will be fine
with refrigerant-air cooling system. It will extract heat at 2-3kW rate.
Though do not expect any faster charging than 70-80kW - fine for a cheap car :)

Well that would not be 100 KW now would it?

I think we can expect probably around 95-96 KW peak which would of course be dependent on SOC but even at low SOC, I would expect something near 90 KW. Expect that to last until maybe 50-60% but wouldn't be surprised if it was closer to 40%. Still a significant step up.
 
DaveinOlyWA said:
I would expect something near 90 KW. Expect that to last until maybe 50-60%
What battery charging peak would expect if you started at a SoC of 10% and battery temp of 110F ?

:lol:
 
DaveinOlyWA said:
arnis said:
Björn verified that newer Leafs have different tapering:
https://www.youtube.com/watch?v=J92fS73qw8c

With this kind of allowance new Leaf with 60kWh pack will be fine
with refrigerant-air cooling system. It will extract heat at 2-3kW rate.
Though do not expect any faster charging than 70-80kW - fine for a cheap car :)

Well that would not be 100 KW now would it?

I think we can expect probably around 95-96 KW peak which would of course be dependent on SOC but even at low SOC, I would expect something near 90 KW. Expect that to last until maybe 50-60% but wouldn't be surprised if it was closer to 40%. Still a significant step up.

Well my estimations were correct. 70kW it is.
http://www.mynissanleaf.com/viewtopic.php?f=55&t=27492

Though even with air circulation/cooling in the pack...cells are very heavily packed, so no more than 2kW of heat extraction.
Though larger pack means C-rate would be slower (at 70kW) than before (at 50kW), that includes driving average load at contant highway speed.
Therefore rapidgate will not be totally solved though better than with 40kW Leafs.
 
arnis said:
DaveinOlyWA said:
arnis said:
Björn verified that newer Leafs have different tapering:
https://www.youtube.com/watch?v=J92fS73qw8c

With this kind of allowance new Leaf with 60kWh pack will be fine
with refrigerant-air cooling system. It will extract heat at 2-3kW rate.
Though do not expect any faster charging than 70-80kW - fine for a cheap car :)

Well that would not be 100 KW now would it?

I think we can expect probably around 95-96 KW peak which would of course be dependent on SOC but even at low SOC, I would expect something near 90 KW. Expect that to last until maybe 50-60% but wouldn't be surprised if it was closer to 40%. Still a significant step up.

Well my estimations were correct. 70kW it is.
http://www.mynissanleaf.com/viewtopic.php?f=55&t=27492

Though even with air circulation/cooling in the pack...cells are very heavily packed, so no more than 2kW of heat extraction.
Though larger pack means C-rate would be slower (at 70kW) than before (at 50kW), that includes driving average load at contant highway speed.
Therefore rapidgate will not be totally solved though better than with 40kW Leafs.

So maybe you can explain the 70 KW charging system with 100 KW peak?
 
This language use suggests Nissan tries to avoid another rapidgate scandal for overpromising.
All they say is that battery could charge at 100kW, but only in very specific circumstances:
not cold (at least 5 bars), not hot (no more than likely 8 bars), when state of charge is
getting close to peak pack voltage (of around 395V) and cell temperatures have been equalized as
some cell cores are cooled much faster than others. Therefore peak 250A (is what conductors will handle).
And due to no cooling (looking at pack production video, there are no fans, no cooling units)
"peak" can be achieved only once per trip (almost the same story with 40kWh overheat).

In most scenarios users are guaranteed to get 70kW charging rate as MAXIMUM expected charging speed
for normal weather (no more than 25*C) (that means below 390V it will be lower, like 65kW and after 395V has been
reached, rate will drop significantly - normal charging speed tapering due to maximum cell voltage limit).
70kW is likely equilibrium point where charging and driving at medium speed in medium weather will
cool down the pack enough for next 180A peak charge rate (70kW).

Like I said, do not EXPECT any faster charging than 70-80kW. The fact that it can do more in ideal conditions
once
is something nobody should rely on for any longer trip.
30 minutes of charging, 35kW of capacity. That gives 2 hours of driving. Again, 30 minutes of charging, 2 hours of driving.
If Leaf e+ had refrigerant cooling unit, it could be able to charge at slightly higher speed than 70kW, maybe 80kW.
But only slightly, as I was also expecting air passages between cells. No. They are extremely heavily packed. Thermal
equalization will take whole night before next 100kW peak can be accepted.
Therefore... it didn't make sense to push refrigerant system into the pack. It would hardly help. I totally agree with engineers.

Looking at my two year old signature, Leaf e+ still gets "Medium range EV" badge from me.
At that time even 40kWh Leaf was totally unheard of.
 
There is an article on electrive.com that states that #Rapidgate fix software update for 2018 Leafs manufactured before May 2018 is now available. I have talked to my local Nissan dealership but so far they don’t know anything about the update. Has anyone had any success getting the update on thier 2018 Leaf?
 
arnis said:
70kW is likely equilibrium point where charging and driving at medium speed in medium weather will
cool down the pack enough for next 180A peak charge rate (70kW).
I'll be surprised if this turns out to be true.
I expect the first charge to be as you described and subsequent charge rates to be in the toilet unless it is freezing outside, just like the 40 kWh LEAF.
 
Well if you drive the 62kWh Leaf normally, where peak energy draw from the battery pack remains below 20kW, the pack can cool itself slowly while driving, since taking 20kW or less from the pack means 0.3C or below, where the cells are not heating up any more. This is why 40kWh battery gets slightly warmer and warmer while you drive. For the 40kWh battery pack this is somewere around 12-13kW, which means 0.3C. This is why the rapidgate charge rate tapering was around this point, as below this energy draw the pack can cool itself down, the cells are not heated any more due to charging or discharging. Since the 62kWh pack is 30% more, you can also draw/or put 30% more energy without heating up the pack.

So if you QC with 70kW (which is only 1.12C compared to the 50kW in the 40kWh battery pack which is 1.25) the heat which builds up during charging is lower, and if you drive after without draining more than 20kW, the pack will cool down till you arrive to the next charge point.

So based on this, I assume, rapidgate will almost never be an issue for the 62kWh Leaf until you do not exceed 100/110kmh speed.
 
^^ The 62 kWh pack is proportionally more dense than the 40 kWh pack; its heat removal per time will be impaired compared to the 40 kWh pack. Moreover, the 40 kWh pack takes the better part of 18 hours once parked to drop below 80F *outside* of the summer.

I'll be happy to make a friendly wager that the 62 kWh pack continues to heat up as you drive unless it is cold outside; that the first charge brings it up to a toasty temperature of ~ 120F, and that the pack stays there on subsequent charges with the charging rate then limited by the heat removal accomplished by the AC cooling
 
This is a non point that I will throw out there anyway. The variables are obvious so you can consider this BS (as I am sure you are more than willing to do) but it would seem the delta would be roughly 20-25º to see cooling of the pack while driving.

The above only works for me. You can now make your own claims.
 
kovadam is on the right track. Such low C- rates for charge (1,2) and discharge (0,3) will have tiny inefficiency.
And 2-hour drive between charging sessions will allow much more cooling just due to time.
 
SageBrush said:
^^ The 62 kWh pack is proportionally more dense than the 40 kWh pack; its heat removal per time will be impaired compared to the 40 kWh pack. Moreover, the 40 kWh pack takes the better part of 18 hours once parked to drop below 80F *outside* of the summer.

I'll be happy to make a friendly wager that the 62 kWh pack continues to heat up as you drive unless it is cold outside; that the first charge brings it up to a toasty temperature of ~ 120F, and that the pack stays there on subsequent charges with the charging rate then limited by the heat removal accomplished by the AC cooling

Yes, it's all about simple thermodynamics and the battery's thermal resistance to ambient, given no significant battery thermal management.
Since all batteries have an internal resistance, battery heat will always be developed whether driving or charging. So it's a simple function
of how much heat is developed, e.g. via vehicle speed and/or charging level, the temperature delta between the battery cells and ambient,
and the overall thermal resistance of the cells to ambient. Thus, the temperature delta is the key controllable variable!
 
lorenfb said:
SageBrush said:
^^ The 62 kWh pack is proportionally more dense than the 40 kWh pack; its heat removal per time will be impaired compared to the 40 kWh pack. Moreover, the 40 kWh pack takes the better part of 18 hours once parked to drop below 80F *outside* of the summer.

I'll be happy to make a friendly wager that the 62 kWh pack continues to heat up as you drive unless it is cold outside; that the first charge brings it up to a toasty temperature of ~ 120F, and that the pack stays there on subsequent charges with the charging rate then limited by the heat removal accomplished by the AC cooling

Yes, it's all about simple thermodynamics and the battery's thermal resistance to ambient, given no significant battery thermal management.
Since all batteries have an internal resistance, battery heat will always be developed whether driving or charging. So it's a simple function
of how much heat is developed, e.g. via vehicle speed and/or charging level, the temperature delta between the battery cells and ambient,
and the overall thermal resistance of the cells to ambient. Thus, the temperature delta is the key controllable variable!

Temperature delta is only a key in how fast the pack cools. If the delta is huge, cools faster, if small, cools lower, however how much the battery pack heats up, is depending on the resistance of the cells (as you wrote), but it is also depending how many current you push through the cells. If the current is low, the heat is low, if the current is high, the heat generated is high. And this is where the C rates come in question, if the C rates are low, current drown from each cell are low, therefore the heat generated is low.

There are 288 cells instead of 196 (or so), so double amount, and the charging power is 70kW (400V 175A) this 175A current is divided into 288 cells so each cell will get 0,6A or 600mA current. In the 40kWh leaf the charge rate is 50kW (400V 125A) this 125A current is divided into 196 cells, which means 0.63A or 630mA current, which is similar for charging. But for discharging (as you drive), if we say 20kWh/100km is a quite faster driving pattern than normal the 40kWh cells are drained with 0.25A or 250mA and the 62kWh batter cells are drained only with 0.17A or 170mA which will result in a much lower heat build up (current was calculated with constant 400V, of course current will increase as battery pack voltage drops, this is only for demo calculations).

Actually the 40kWh battery pack is not heating up, if you drain constantly less power than 12kW. With 62kWh pack this is around 20kW probably, so this means if you drive normally, and drain less power from the battery pack, it can cool down instead of heating up, like the 40kWh pack. If you achieve an average consumption of 15kWh/100km, then you already heated up the 40kWh pack a little bit, however the 62kWh pack could cooled down a little bit with this. Check out on youtube Jame's (Lemon Tea Leaf) video about how he achieved to keep the temp down. He managed to cool down the pack by several °C through not taking more power from the pack as 12-15kW.

How fast it's cooling down, depends on the temperature difference (delta). But the heat build up depends on the current that flows through the cells.
 
kovadam said:
lorenfb said:
SageBrush said:
^^ The 62 kWh pack is proportionally more dense than the 40 kWh pack; its heat removal per time will be impaired compared to the 40 kWh pack. Moreover, the 40 kWh pack takes the better part of 18 hours once parked to drop below 80F *outside* of the summer.

I'll be happy to make a friendly wager that the 62 kWh pack continues to heat up as you drive unless it is cold outside; that the first charge brings it up to a toasty temperature of ~ 120F, and that the pack stays there on subsequent charges with the charging rate then limited by the heat removal accomplished by the AC cooling

Yes, it's all about simple thermodynamics and the battery's thermal resistance to ambient, given no significant battery thermal management.
Since all batteries have an internal resistance, battery heat will always be developed whether driving or charging. So it's a simple function
of how much heat is developed, e.g. via vehicle speed and/or charging level, the temperature delta between the battery cells and ambient,
and the overall thermal resistance of the cells to ambient. Thus, the temperature delta is the key controllable variable!

Temperature delta is only a key in how fast the pack cools. If the delta is huge, cools faster, if small, cools lower, however how much the battery pack heats up, is depending on the resistance of the cells (as you wrote), but it is also depending how many current you push through the cells. If the current is low, the heat is low, if the current is high, the heat generated is high. And this is where the C rates come in question, if the C rates are low, current drown from each cell are low, therefore the heat generated is low.

There are 288 cells instead of 196 (or so), so double amount, and the charging power is 70kW (400V 175A) this 175A current is divided into 288 cells so each cell will get 0,6A or 600mA current. In the 40kWh leaf the charge rate is 50kW (400V 125A) this 125A current is divided into 196 cells, which means 0.63A or 630mA current, which is similar for charging. But for discharging (as you drive), if we say 20kWh/100km is a quite faster driving pattern than normal the 40kWh cells are drained with 0.25A or 250mA and the 62kWh batter cells are drained only with 0.17A or 170mA which will result in a much lower heat build up (current was calculated with constant 400V, of course current will increase as battery pack voltage drops, this is only for demo calculations).

Actually the 40kWh battery pack is not heating up, if you drain constantly less power than 12kW. With 62kWh pack this is around 20kW probably, so this means if you drive normally, and drain less power from the battery pack, it can cool down instead of heating up, like the 40kWh pack. If you achieve an average consumption of 15kWh/100km, then you already heated up the 40kWh pack a little bit, however the 62kWh pack could cooled down a little bit with this. Check out on youtube Jame's (Lemon Tea Leaf) video about how he achieved to keep the temp down. He managed to cool down the pack by several °C through not taking more power from the pack as 12-15kW.

How fast it's cooling down, depends on the temperature difference (delta). But the heat build up depends on the current that flows through the cells.

Nothing really new added, basically just paraphrasing the same as was previously posted! DaveinOlyWA performed a basic test on his
40kWh Leaf that indicated the battery's internal resistance to be about 100 milliohms. So when charging at about 40kW the battery
will be dissipating about 1,000 watts (100^2 amps X .100 ohms). Typically when driving at about 60 MPH (level terrain), the battery
current is about 30 - 40 amps, which results in about 90 to 160 watts of battery power dissipation - heat. Given a high thermal battery
resistance to ambient for the Leaf, the temperature gradient to ambient needs to be significant, when multiple sequential QCs
occur to prevent excess battery heat, or limiting successive high current charging.
 
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