Arizona battery degradation/ heat precaution questions

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.
GaryHere said:
I should have the numbers from the test today, I'm at 26% SOC. ;)
Feel free to post them now. The test does not require exactly 20%, any more than it requires exactly 80% ;-)

This symbol
~
means 'approximately'
 
SageBrush said:
GaryHere said:
I should have the numbers from the test today, I'm at 26% SOC. ;)
Feel free to post them now. The test does not require exactly 20%, any more than it requires exactly 80% ;-)

This symbol
~
means 'approximately'

Oh ok

I didn't drive much today so still at 25%

Tonight I'll probably drive to get pizza so I'll post the numbers then.

Thanks again for all. :D
 
SageBrush said:
GaryHere said:
I should have the numbers from the test today, I'm at 26% SOC. ;)
Feel free to post them now. The test does not require exactly 20%, any more than it requires exactly 80% ;-)

This symbol
~
means 'approximately'

Here are the results------>

RFNauaY.jpg



Exactly 80% to 20% SOC just now.

49.3 miles driven
4.9/kWh


I really dont know if I passed or failed. I tried to look at your figures and got kinda lost :(

Sorry.
 
I'm going to withdraw my guess. I tend to make mistakes this late at night. ;-) I will say that based on an 80% charge you got good range and great efficiency.
 
GaryHere said:
SageBrush said:
GaryHere said:
Exactly 80% to 20% SOC just now.

49.3 miles driven
4.9 miles/kWh

During this test you consumed
49.3 miles / 4.9 miles/kWh = 10.06 kWh and you used 60% of your battery capacity

So the full battery capacity would be
10.06/0.6 = 16.77 kWh **

Interp: I'd do a couple more tests to be sure, but based on this test the 12th bar should drop any day now

----
Are you able to recharge at a station that reports energy delivered ?
It would be nice to confirm the results of this first test

**
Two key assumptions here:
The miles/kWh meter was reset at the beginning of the test and not reset thereafter
No additional recharges during the test
 
SageBrush said:

During this test you consumed
49.3 miles / 4.9 miles/kWh = 10.06 kWh and you used 60% of your battery capacity

So the full battery capacity would be
10.06/0.6 = 16.77 kWh **

Interp: I'd do a couple more tests to be sure, but based on this test the 12th bar should drop any day now

----
Are you able to recharge at a station that reports energy delivered ?
It would be nice to confirm the results of this first test

**
Two key assumptions here:
The miles/kWh meter was reset at the beginning of the test and not reset thereafter
No additional recharges during the test

Thanks for your math, I definitely wouldn't been able to!

Question on the first bolded:

The 0.6 figure is the 60% I used?

And then that's taken and times the kWh used we arrive at 16.77 kWh capacity on a supposedly 24 kWh battery (21 available when it's new) which leads to my second bolded.....NOT good. :(

Aww well.

I'll do more tests. I think on that Chargepoint chargers it shows that kWh delivered however the Blink don't due to here in AZ the rates go by time, not amount of kWh.

I have a screenshot somewhere of how much kWh was put out by the CP charger in an hours time; dunno if that would help but I'll post it if so.

Thanks very much for the math help!

I guess trading this in to Carmax when I get the title from Carvana might be happening depending on more tests. With our heat here and getting possibly degraded 15% when the first bar goes likely soon, I don't think it wise to keep the car.

A shame really. I like it. But it is slowly turning me off to keep it but we'll see what happens with more testing etc and I'd like to get that Leaf Spy on it as well before I trade it in, if I even do or would.
 
GaryHere said:
The 0.6 figure is the 60% I used?

And then that's taken and times the kWh used we arrive at 16.77 kWh capacity on a supposedly 24 kWh battery (21 available when it's new) which leads to my second bolded.....NOT good. :(
Yes, the 0.6 is the 60% SoC used
And the the kWh used divided by
the SoC used gives the total battery capacity.

To see why the arithmetic works this way, imagine you first want to know how many kWh you have in ONe percent:
That would be 10.06 kwh / 60 = 0.167 kWh
Then 100% SoC is 0.167 * 100 = 16.7 kWh

Recharging at a place that reports kWh from the meter is a good idea.
Your other choice is to buy an OBDII adapter. If LeafSpy agrees with 16.7 kWh you have a reliable answer. If not, then more testing is in order.

Sorry I could not be the bearer of better news but it is not terrible. At 4.9 miles a kWh you have a total range of 4.9*16.7 = ~ 80 miles, or figure 70 miles with a little security. The tougher question is how quickly the battery will degrade in Tuscon.

I wish you well, however you decide

-- Eric
 
SageBrush said:
GaryHere said:
The 0.6 figure is the 60% I used?

And then that's taken and times the kWh used we arrive at 16.77 kWh capacity on a supposedly 24 kWh battery (21 available when it's new) which leads to my second bolded.....NOT good. :(
Yes, the 0.6 is the 60% SoC used
And the the kWh used divided by
the SoC used gives the total battery capacity.

To see why the arithmetic works this way, imagine you first want to know how many kWh you have in ONe percent:
That would be 10.06 kwh / 60 = 0.167 kWh
Then 100% SoC is 0.167 * 100 = 16.7 kWh

Recharging at a place that reports kWh from the meter is a good idea.
Your other choice is to buy an OBDII adapter. If LeafSpy agrees with 16.7 kWh you have a reliable answer. If not, then more testing is in order.

Sorry I could not be the bearer of better news but it is not terrible. At 4.9 miles a kWh you have a total range of 4.9*16.7 = ~ 80 miles, or figure 70 miles with a little security. The tougher question is how quickly the battery will degrade in Tuscon.

I wish you well, however you decide

-- Eric

First, thank you very much Eric for ALL your replies here; I'm very grateful and appreciative for sure; you've helped tremendously!

I understand the math now, that's a good test in absence of the Leaf Spy.

Not too bad a range left I suppose.

Do you think the lessened capacity is typical for the age of the battery? 3 years old?

I don't think it's been baking too long in heat of those three years since it was in a non desert environment before.

Yes the tougher question is how quickly from this lessened capacity will it degrade with our temps here. And how much will I get outta this car long term.

As it stands today, I'm leaning towards trading it in for a vehicle liquid cooled. I'd like to stay all electric but I suppose another Volt could be a possibility. Either that or back to the Fiat with no repair facility within 110 miles. Lol.

I'll see, I have time to decide, don't want to be so hasty with this since I'm going to be out money unless I sold it to a private party.

In the meantime I'll run another test.

One other question on my mind.

Wouldn't the speed driven influence those results of the kWh used?

I mean if I drove at 75mph from 80 to 20% SOC wouldn't that yield different results than my driving this recent test at about 20-35 mph?

Just curious. Thanks again.

Have a great day.
 
LeftieBiker said:
I'm going to withdraw my guess. I tend to make mistakes this late at night. ;-) I will say that based on an 80% charge you got good range and great efficiency.

My guess last night was a pack with between 12% and 15% capacity loss, so I guess I was close enough.
 
GaryHere said:
Wouldn't the speed driven influence those results of the kWh used?

I mean if I drove at 75mph from 80 to 20% SOC wouldn't that yield different results than my driving this recent test at about 20-35 mph?

The battery measurement shows how much kWh capacity the battery has. Once the battery capacity is known, you can use that capacity in any way you want. Driving faster will use more power due to increased drag and result in less range. For max range, drive slower.

For this type of measurement, both the numerator and denominator would be changed by equal amounts so the battery capacity result should be unchanged.
 
GaryHere said:
Do you think the lessened capacity is typical for the age of the battery? 3 years old?
I'd say pretty average.

Excuse my nature, but let me ask one last time:
Only one charge to bring the SoC up to ~ 80% at the start of the test, and no recharges since, right ?
And second, the miles/kWh meter was zeroed when SoC hit 80% -- again right ?
 
goldbrick said:
For this type of measurement, both the numerator and denominator would be changed by equal amounts so the battery capacity result should be unchanged.
ACCURACY POLICE HERE. TAKE YOUR HANDS OFF THE KEYBOARD.

Not equal amounts, equal proportions.
 
goldbrick said:
GaryHere said:
Wouldn't the speed driven influence those results of the kWh used?

I mean if I drove at 75mph from 80 to 20% SOC wouldn't that yield different results than my driving this recent test at about 20-35 mph?

The battery measurement shows how much kWh capacity the battery has. Once the battery capacity is known, you can use that capacity in any way you want. Driving faster will use more power due to increased drag and result in less range. For max range, drive slower.

For this type of measurement, both the numerator and denominator would be changed by equal amounts so the battery capacity result should be unchanged.

Ok, I get it now, thanks for the reply :)



SageBrush said:
GaryHere said:
Do you think the lessened capacity is typical for the age of the battery? 3 years old?
I'd say pretty average.

Excuse my nature, but let me ask one last time:
Only one charge to bring the SoC up to ~ 80% at the start of the test, and no recharges since, right ?
And second, the miles/kWh meter was zeroed when SoC hit 80% -- again right ?

Ahh ok so average, until our heat gets to it long term then the chit hits the fan LOL

Correct---- NO charges since that 80%

And correct as well on zeroing the miles/kWh meter when I was at 80%


I just got the first LBM, I have to admit that indicator that looks like a gas pump with a plug is pretty dam cool :)
 
I would rather see you run a longer range/battery capacity test if you are concerned before deciding to give up the car. I notice that the SOC% and SOC bar drops are not always linear so a test from full charge to LBW (or even VLBW) would give more accurate results. Also, I find that the mi/kWh number on the dash is generally a little high compared to measuring charging energy from the wall with an accurate watt-hour meter and calculating the actual miles/kWh so you may have actually used more than 10 kWh from the battery during your test (which would imply that the battery has more capacity than Eric calculated).
 
GerryAZ said:
I would rather see you run a longer range/battery capacity test if you are concerned before deciding to give up the car. I notice that the SOC% and SOC bar drops are not always linear so a test from full charge to LBW (or even VLBW) would give more accurate results. Also, I find that the mi/kWh number on the dash is generally a little high compared to measuring charging energy from the wall with an accurate watt-hour meter and calculating the actual miles/kWh so you may have actually used more than 10 kWh from the battery during your test (which would imply that the battery has more capacity than Eric calculated).

Hi. Ok sounds good. I certainly have plenty of time as I asked about the paperwork today and Carvana said likely that title won't get to me till late July.

Then I suppose I'll decide then what to do with it.

Thanks for your reply, stay cool up there in Phx.
 
I want to thank all the wonderful posters here whom in the last few weeks helped me tremendously especially SageBrush Eric whom I thanked thru the PMs.

On Saturday I'm trading in my Leaf and getting my Fiat back.

The lack of TMS was too much a concern for me and the Fiat has two systems, active and passive for cooling so it seemed like the right thing to do before I drop a bar and I really lose it. LOL.

Thanks to all and have a great summer and safe Leaf travels and adventures for you all. :D

Gary
 
Back
Top