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Re: 2019 Leaf battery overheating

Posted: Mon May 20, 2019 10:14 am
by SageBrush
metricus wrote: Judging by ByornTesla's
TeslaBjorn :)

Re: 2019 Leaf battery overheating

Posted: Mon May 20, 2019 10:19 am
by SageBrush
metricus wrote: We'll see.... I'll pop in the dongle when it arrives and report back.
Per Bjorn, heat related throttling starts at 40C. I'm willing to bet good money that the middle of the LEAF temperature gauge easily straddles the throttle zone.

Get ready to be surprised. The LEAF temperature gauge is not just poor, it is misleading.

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 6:27 am
by DaveinOlyWA
lorenfb wrote:
SageBrush wrote: The 62 kWh model is improved in terms of rapid-gate
That's yet to be determined, i.e. basically no data exists compared to the 40 kWh except anecdotal - especially via LeafSpy.
There is already one report of seeing 25 KW charging speed @ 20% SOC so looks like nothing has changed.

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 8:22 am
by SageBrush
DaveinOlyWA wrote:
lorenfb wrote:
SageBrush wrote: The 62 kWh model is improved in terms of rapid-gate
That's yet to be determined, i.e. basically no data exists compared to the 40 kWh except anecdotal - especially via LeafSpy.
There is already one report of seeing 25 KW charging speed @ 20% SOC so looks like nothing has changed.
Wrong conclusion. In the best case the cooling is fairly anemic* and only operates while the car is on and connected to a charger. It is still possible to reach heat related throttling fairly easily. So finding a condition that is throttled in no way means that a cooling method has not been added. Just because 'everything' has not changed does not mean that 'nothing' has changed. Hyperbole turns your reasoning ability to mush.

Bjorn reported that the battery stays at 40C during a 25 kW charge in the e-NV200. If my arithmetic is correct that works out to ~ 240 watts of heat dissipation presuming 50 mOhm resistance.

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 10:15 am
by lorenfb
SageBrush wrote: Wrong conclusion. In the best case the cooling is fairly anemic* and only operates while the car is on and connected to a charger. It is still possible to reach heat related throttling fairly easily. So finding a condition that is throttled in no way means that a cooling method has not been added. Just because 'everything' has not changed does not mean that 'nothing' has changed. Hyperbole turns your reasoning ability to mush.
Where're the data/reports that indicate that the Plus has a very basic TMS? You haven't posted any links! You're better than that.
SageBrush wrote:Bjorn reported that the battery stays at 40C during a 25 kW charge in the e-NV200. If my arithmetic is correct that works out to ~ 240 watts of heat dissipation presuming 50 mOhm resistance.
And where did the 50 mOhm assumed battery resistance come from?

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 10:20 am
by SageBrush
lorenfb wrote: And where did the 50 mOhm assumed battery resistance come from?
As usual, the ether. I took the optimistic side of your readings on an old 2013 LEAF

verry sketchy :lol:

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 10:40 am
by lorenfb
SageBrush wrote:
lorenfb wrote: And where did the 50 mOhm assumed battery resistance come from?
As usual, the ether. I took the optimistic side of your readings on an old 2013 LEAF
Yes, but the Plus should have 24/62 X .050 ohms (~ .020) of my 2013, given the larger battery size - more cells/pouches in parallel.
If the battery resistance hasn't really changed, e.g. marginal Plus chemistry, that can explain the added battery heat occurring
for the Plus while charging and high speed driving.

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 11:08 am
by SageBrush
lorenfb wrote:
SageBrush wrote:
lorenfb wrote: And where did the 50 mOhm assumed battery resistance come from?
As usual, the ether. I took the optimistic side of your readings on an old 2013 LEAF
Yes, but the Plus should have 24/62 X .050 ohms (~ .020) of my 2013, given the larger battery size - more cells/pouches in parallel.
If the battery resistance hasn't really changed, e.g. marginal Plus chemistry, that can explain the added battery heat occurring
for the Plus while charging and high speed driving.
I thought about that but the 40 kWh pack (that I think DaveInOly tested, IIRC) showed similar resistance results so I decided to err on the side of disappointing AESC engineering.

Re: 2019 Leaf battery overheating

Posted: Tue May 21, 2019 4:01 pm
by lorenfb
SageBrush wrote:
lorenfb wrote:
SageBrush wrote: As usual, the ether. I took the optimistic side of your readings on an old 2013 LEAF
Yes, but the Plus should have 24/62 X .050 ohms (~ .020) of my 2013, given the larger battery size - more cells/pouches in parallel.
If the battery resistance hasn't really changed, e.g. marginal Plus chemistry, that can explain the added battery heat occurring
for the Plus while charging and high speed driving.
I thought about that but the 40 kWh pack (that I think DaveInOly tested, IIRC) showed similar resistance results so I decided to err on the side of disappointing AESC engineering.
Here's what's needed (Tesla app TM-Spy during Ludicrous mode):

https://teslamotorsclub.com/tmc/attachm ... ng.112153/

Note; The current indicated is off by a factor of 10 (S/B 1300 amps) as is the power. The MS battery resistance is about 77 mohms.

from the Tesla website;

https://teslamotorsclub.com/tmc/threads ... ata.63051/

Turbo3:
Here is a screen capture of what I am working on next for TM-Spy. In Settings/Options you can place TM-Spy into a mode where it just sits and captures battery voltage and amps at a CAN bus rate of 100 per second. You can do this with the current release and see the ELM transmit LED stay on solid but the next version lets you see the data capture.

This screenshot is from an "Insane' run I was taken on last week. The amps at the peck is 1300 which is right on spec. Note how the voltage sags when you start pulling 1300 amps from it. The graph moves from right to left which is why you see -16 seconds on the left edge. You can also see the regen power and the battery voltage go above the voltage when the car was stopped (near 0 power).


Re: 2019 Leaf battery overheating

Posted: Wed May 22, 2019 6:34 am
by DaveinOlyWA
SageBrush wrote:
metricus wrote: We'll see.... I'll pop in the dongle when it arrives and report back.
Per Bjorn, heat related throttling starts at 40C. I'm willing to bet good money that the middle of the LEAF temperature gauge easily straddles the throttle zone.

Get ready to be surprised. The LEAF temperature gauge is not just poor, it is misleading.

LEAF Spy says throttling starts over 86ยบ give or take a few. Below that, you will get full speed charging (~125 amps on a "50 KW" charger if you will) but a lower knee. Above that, you will get a higher knee but a lower current at the start of the charge.

This assumes your starting SOC is below the knee.