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Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Fri Jun 22, 2018 5:59 pm
by dwl
SageBrush wrote:
dwl wrote: What does everyone else on this forum think of a reported 2.2% SoC and 349.62V pack, 3.639V cell voltages?
My first thought is that pack depletion is determined by the weakest cell.
Good point, so the minimum cell voltage is also important. Note this is the average voltage so provided not a large inbalance does the SoC seem far too low for this voltage?

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Fri Jun 22, 2018 7:09 pm
by SageBrush
dwl wrote:
SageBrush wrote:
dwl wrote: What does everyone else on this forum think of a reported 2.2% SoC and 349.62V pack, 3.639V cell voltages?
My first thought is that pack depletion is determined by the weakest cell.
Good point, so the minimum cell voltage is also important. Note this is the average voltage so provided not a large inbalance does the SoC seem far too low for this voltage?
That was my first thought. I so rarely drive my LEAF down to low battery levels, I don't have a ready voltage handy off the top of my head. I bet @lorenfb would have a better idea.

It would be trivial for anybody interested to find out if they have LeafSpy

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Fri Jun 22, 2018 7:59 pm
by jbuntz
dwl wrote:
SageBrush wrote:
dwl wrote: What does everyone else on this forum think of a reported 2.2% SoC and 349.62V pack, 3.639V cell voltages?
My first thought is that pack depletion is determined by the weakest cell.
Good point, so the minimum cell voltage is also important. Note this is the average voltage so provided not a large inbalance does the SoC seem far too low for this voltage?
At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
When the QC charger said 19.8kWh delivered did that include the losses in the charger too? I noticed a big fan on the charger blowing hot air. If not then a more accurate estimate of capacity might be 19.8/28.5 or 69% but there would be some loss related to the battery heating up from 100° to 120° Plus the ac was on for 30 minutes.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Fri Jun 22, 2018 9:39 pm
by SageBrush
jbuntz wrote:
dwl wrote:
SageBrush wrote: My first thought is that pack depletion is determined by the weakest cell.
Good point, so the minimum cell voltage is also important. Note this is the average voltage so provided not a large inbalance does the SoC seem far too low for this voltage?
At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
When the QC charger said 19.8kWh delivered did that include the losses in the charger too? I noticed a big fan on the charger blowing hot air. If not then a more accurate estimate of capacity might be 19.8/28.5 or 69% but there would be some loss related to the battery heating up from 100° to 120° Plus the ac was on for 30 minutes.
Good points.

I keep forgetting this was a DC charger. I don't know if the 19.8 kWh included the charger losses. It is probably vendor specified.
A/C use would be power diverted away from the battery, so the actual battery capacity is less.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 3:59 am
by dwl
jbuntz wrote:At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
At 6 GIDs was turtle light coming on? Still a lot of voltage for turtle - the lowest cell was probably still about 3.4V.

Only 3 GIDs (0.24kWh @ 80W/GID) from 349V to 331V seems weird. I have seen one car which had 6kWh between those two voltages which made more sense. This is looking like reporting gone wrong and an interesting case study.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 5:15 am
by jbuntz
dwl wrote:
jbuntz wrote:At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
At 6 GIDs was turtle light coming on? Still a lot of voltage for turtle - the lowest cell was probably still about 3.4V.

Only 3 GIDs (0.24kWh @ 80W/GID) from 349V to 331V seems weird. I have seen one car which had 6kWh between those two voltages which made more sense. This is looking like reporting gone wrong and an interesting case study.
The lowest voltage was 3.426 and turtle had not showed up yet.

From one time back in October I got down to 4 gids. The spread was 233mV and the low was 2.832. Pack at 282v I sense that once you get below 10 gids it is dropping off really fast. On this one, turtle was showing.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 6:33 am
by DaveinOlyWA
Overheatingleaf wrote:Did another quick charge yesterday from 18% on the dash, on s pretty hot day. Did it in landscape mode this time. Looks like my charge starts to slow down around 50%. Not sure if it's from the battery temp or just a normal charge curve. I'll see if I can embed the picture here.

https://photos.app.goo.gl/6b9ekcFCQkQRATCe6
This is a 30 kwh LEAF? WOW, your ramp down started early. Batt temps not high enough to start restricting charge. I think you have to be at 11 temperature bars for that to start happening. I normally saw ramp down starting no lower than 75% up to the low 80's%

FYI; I had my pack to 125 º range many many times.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 6:37 am
by DaveinOlyWA
SageBrush wrote:
jbuntz wrote:
dwl wrote: Good point, so the minimum cell voltage is also important. Note this is the average voltage so provided not a large inbalance does the SoC seem far too low for this voltage?
At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
When the QC charger said 19.8kWh delivered did that include the losses in the charger too? I noticed a big fan on the charger blowing hot air. If not then a more accurate estimate of capacity might be 19.8/28.5 or 69% but there would be some loss related to the battery heating up from 100° to 120° Plus the ac was on for 30 minutes.
Good points.

I keep forgetting this was a DC charger. I don't know if the 19.8 kWh included the charger losses. It is probably vendor specified.
A/C use would be power diverted away from the battery, so the actual battery capacity is less.
No its power to the car. Now realize "that" power to the car also has losses but it fairly efficient. My average from DCFCs runs 94-96% . My guess is range is not that wide, its the accuracy of Nissan instrumentation that makes it that "variable"

The best way to measure power to the battery is thru LEAF Spy. I reset power meter before charge starts and it only records what is going to battery. You can test this theory by starting car and turning a power draw like AC or something.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 1:10 pm
by dwl
jbuntz wrote:
dwl wrote:
jbuntz wrote:At 9 gids the voltage spread was only 14mv. At 6 gids (turtle) it was 68mv 331v pack. Hx 60%.
At 6 GIDs was turtle light coming on? Still a lot of voltage for turtle - the lowest cell was probably still about 3.4V.

Only 3 GIDs (0.24kWh @ 80W/GID) from 349V to 331V seems weird. I have seen one car which had 6kWh between those two voltages which made more sense. This is looking like reporting gone wrong and an interesting case study.
The lowest voltage was 3.426 and turtle had not showed up yet.

From one time back in October I got down to 4 gids. The spread was 233mV and the low was 2.832. Pack at 282v I sense that once you get below 10 gids it is dropping off really fast. On this one, turtle was showing.
It looks your car has changed estimations significantly since last October. Only 2 GIDs between lowest cell at 3.426V now (6 GIDs) and 4 GIDs at 2.832V back then should have far more kWh (GIDs) difference reported which is probably still sitting in the pack.

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Posted: Sat Jun 23, 2018 1:20 pm
by jbuntz
dwl wrote:
jbuntz wrote:
dwl wrote:At 6 GIDs was turtle light coming on? Still a lot of voltage for turtle - the lowest cell was probably still about 3.4V.

Only 3 GIDs (0.24kWh @ 80W/GID) from 349V to 331V seems weird. I have seen one car which had 6kWh between those two voltages which made more sense. This is looking like reporting gone wrong and an interesting case study.
The lowest voltage was 3.426 and turtle had not showed up yet.

From one time back in October I got down to 4 gids. The spread was 233mV and the low was 2.832. Pack at 282v I sense that once you get below 10 gids it is dropping off really fast. On this one, turtle was showing.
It looks your car has changed estimations significantly since last October. Only 2 GIDs between lowest cell at 3.426V now (6 GIDs) and 4 GIDs at 2.832V back then should have far more kWh (GIDs) difference reported which is probably still sitting in the pack.
I got it to 4 gids. Turtle showing and unable to put it in drive. Low cell at 2.869 high 3.099 pack 286.48 temp 105F. Charging now 234V 29A