80% Charge only 9 bars?

[Ingineer]

I'll say again: 80% charge is really 80% SoC, Full charge is usually 94-95% SoC. This means there is about 15% capacity difference from 80% to "Full".

Reading SoC from a Gidmeter is not accurate, as it's based on 281 Gids (22.48kWh) = 100% SoC.

-Phil

 

[planet4ever]

I'll say again: 80% charge is really 80% SoC, Full charge is usually 94-95% SoC. This means there is about 15% capacity difference from 80% to "Full". Reading SoC from a Gidmeter is not accurate, as it's based on 281 Gids (22.48kWh) = 100% SoC.

But wouldn't that mean the "74%" tzzhc4 is seeing is really gids/281 = 0.74, so gids ~= 208?
That in turn, per the information you have given us, Phil, would mean his 80% charge is about 16.64kWh.
Based on this, and what you say about 80%, his total battery capacity is something like 20.8kWh.
This is down very significantly from the presumed original 24kWh; in fact about 13% down.

Is there something wrong with my assumptions or calculations?

Ray

P.S. I still don't see what this has to do with 9 bars vs. 10 bars. If the battery capacity was down to 10kWh, and you charged fully, you would still see 12 bars. I would expect that an 80% charge would still (usually) show 10 bars. My 9-bar theory is that the battery has warmed up since it finished charging, and that means its capacity has increased, so you are no longer at 80% SoC.

 

[Ingineer]

A "full" charge is typically around 94-95% SoC, while an 80% charge is actually to 80% SoC. My last "full" charge stopped at just over 94% SoC which was 278 "Gids" or 22240 watt-hours. Also keep in mind, the battery contactor opens at around 2% SoC, so you only get about 92% usable per full charge. I've calculated that 100% SoC (if you could reach it) would be 23512 watt-hours. (on my car anyway) Knowing the top ~5% (1176wH) and the bottom ~2% (470wH) can't really be used, that leaves 21866wH actual usable from "full" to turtle, and 18340wH usable from 80% to turtle. Since there is a significantly wide variation from one "full" charge to the next, it's not an accurate test to charge to full and expect repeatable results. It would be more accurate to charge to 80%.

-Phil

 

[Ingineer]

Ray, you are right about the bars. The Battery ECU will attempt to recalculate SoC when parameters change, and thus the SoC could do as you mention.

 

[edatoakrun]

A "full" charge is typically around 94-95% SoC, while an 80% charge is actually to 80% SoC. My last "full" charge stopped at just over 94% SoC which was 278 "Gids" or 22240 watt-hours. Also keep in mind, the battery contactor opens at around 2% SoC, so you only get about 92% usable per full charge. I've calculated that 100% SoC (if you could reach it) would be 23512 watt-hours. (on my car anyway) Knowing the top ~5% (1176wH) and the bottom ~2% (470wH) can't really be used, that leaves 21866wH actual usable from "full" to turtle, and 18340wH usable from 80% to turtle. Since there is a significantly wide variation from one "full" charge to the next, it's not an accurate test to charge to full and expect repeatable results. It would be more accurate to charge to 80%.

-Phil

So, the most accurate measurement of loss of total battery capacity (the unattainable 100% SOC level) by a LEAF owner with a Gid meter might be to charge to 80%, and compare the Gid count with those from their tests of their battery when new, right?

Have you noticed any correlation of the varying 94%-95% SOC rate at "100%" charge, with temperature?

Have you had the opportunity to measure this on a very hot battery?

Has anyone excluded the possibility that an "11 bar battery" may be "100%" charging to less than the 94%-95% SOC level?

If I were A Nissan executive trying to figure out how to sell a BEV with an 8 year 100,000 mile battery warranty, I would certainly try to design the battery charge management to prevent premature failure.

One way to do this would be to reduce the percentage of SOC available to the driver from the initial `92%, if conditions (high temps) indicated a LEAF's battery could not tolerate access to this high a level of SOC, for the full warranty period.

 

[Ingineer]

I would have to say a more accurate test would be to discharge to at least 50% SoC and then do a full charge. Going to "full" is going to be a more accurate stopping point. Obviously it would be a better comparison if temperatures were all constant, but until I get LEAFSCAN into your hands, it's impossible to really tell what's going on there under the floor.

80% charges are going to include any error from the hall-effect coulomb-counter, so why add more error??

Do a full charge, read the Gids, multiply by 80, subtract 2%, and that's your rough pack capacity in watt-hours. (I'd say there's at least a +/- 2% margin though)

-Phil

 

[Ingineer]

Also keep in mind, that of the 24kWh stated capacity, only roughly 93% of that is "usable", which IS the headroom Nissan provided (mostly on the top end) to ensure long life. (5% top)

Other than the very small percentage of these Phoenix problem cars, we really haven't seen any problems, so my conclusion is Nissan did a good job overall.

If they goofed and somehow the heat in AZ is killing packs, I'm sure they'll come up with a solution. Keep in mind a huge organization like Nissan moves very slow and deliberately. I wouldn't expect anything from them anytime soon.

To me, 15% is a large loss to have in about a year. I would be upset if my Leaf experienced this, but let's give Nissan time to research it. They know more than we do about the Leaf.

-Phil

 

[mwalsh]

To me, 15% is a large loss to have in about a year. I would be upset if my Leaf experienced this, but let's give Nissan time to research it. They know more than we do about the Leaf.

To me too. UNLESS this is the majority of the loss occurring in the first year (OK, 18 months) of ownership we had previously surmised might happen. If we settle down again now to just some marginal loss over the next few years, I think the hysteria will have been for nothing. It does seem mighty odd to me though, that the affected cars have gone from relatively small/benign losses during the entire period up to the last couple of weeks, to falling over metaphorical cliff all of a sudden!

One thing that troubles me about my own car is that I have not seen any upward movement in available capacity following the last four full charges. I usually see several consecutive days of lesser charge followed by a bump as my car charges on an equalization cycle. Or it has vacillated between a higher and lower charge number for several consecutive nights charges. I have not seen any of that at all since I started making a note of what was happening this week, though I am not yet at the lowest charge number I've seen on my car during the last two to three weeks. However, a prolonged period with daily decreases in available charge now that I'm really noticing it will be cause for further concern on my part that all is not well!

Edit: Which I suppose leaves me an opening to post today's numbers thus far:

0 miles / 89.3 / 251 Gids / 393.5 v
30.5 miles / 59.4 / 167 Gids / 378.5 v
61 miles / 27.0 / 76 Gids / 366 v

Note that represents 10 Gids down from Sunday's full charge thus far. Loosing 3-4 per charge cycle, if this continues unabated.

 

[tzzhc4]

Edit: Which I suppose leaves me an opening to post today's numbers thus far:

0 miles / 89.3 / 251 Gids / 393.5 v
30.5 miles / 59.4 / 167 Gids / 365 v

Note that represents 10 Gids down from Sunday's full charge thus far. Loosing 3-4 per charge cycle, if this continues unabated.

My numbers today after charging to 100%:

100% charge on the vehicle / 88.9% on the gidmeter/ 250 Gids

Guess I will check daily and see if I too am using 3-4 per charge cycle

 

[surfingslovak]

100% charge on the vehicle / 88.9% on the gidmeter/ 250 Gids

Tzzhc4, are you in Dallas? How do you park your car overnight? Please keep the data coming.

 

[tzzhc4]

100% charge on the vehicle / 88.9% on the gidmeter/ 250 Gids

Tzzhc4, are you in Dallas? How do you park your car overnight? Please keep the data coming.

Yes I am in Dallas, Texas. I park my LEAF overnight in our garage which as of last year is air conditioned to ~80 degrees. I will be tracking by %/# of gids daily.

 

[tzzhc4]

To me, 15% is a large loss to have in about a year. I would be upset if my Leaf experienced this, but let's give Nissan time to research it. They know more than we do about the Leaf.

Agreed, it is just unnerving but then again it is part of being an early adopter. Hopefully the loss will slowdown otherwise the car won't have much range in another 2 years.

 

[surfingslovak]

My numbers today after charging to 100%:
100% charge on the vehicle / 88.9% on the gidmeter/ 250 Gids
Guess I will check daily and see if I too am using 3-4 per charge cycle

One would think that your air-conditioned garage should have an impact. I see that you are a member of the 80% club. How is the car parked during the day? Please consider creating a public Google doc, which would allow several folks to follow the data you enter over time.

TickTock has pioneered that idea, and his data collection is quite impressive. I did something similar for the ActiveE field trial, which apparently had an impact. I was told that they flew in engineers to work on the car, and Coulomb is updating firmware on some of their stations as a result.

The spreadsheet doesn't have to be all that detailed, but the more data we have, the better.

 

[mwalsh]

Agreed, it is just unnerving but then again it is part of being an early adopter. Hopefully the loss will slowdown otherwise the car won't have much range in another 2 years.

2 years? If my losses continue like this, my car will be a brick by September! :shock: I'm really, really hoping for a balancing uptick after charging gets done this morning. It's been 5 charges...I really should be due one.

 

[surfingslovak]

2 years? If my losses continue like this, my car will be a brick by September! :shock: I'm really, really hoping for a balancing uptick after charging gets done this morning. It's been 5 charges...I really should be due one.

Mike, I believe that you were at 5% capacity loss in April, and are down another 5% a month later. I could be wrong, but it would appear that one of your battery modules is going bad. We'll know soon enough.

One more thing: I remember you posting Gid numbers from your car last fall. Did you keep a log by any chance? I haven't seen anything between October and April on the forum. This would be helpful in figuring out when the decline started. Would you remember? There appears to be one instance of 8% lower charge in early October, when your car was less than a year old. That's pretty unusual from what I've seen. Did your Gid number always fluctuate this much?

How does your charging routine look like? 100% on work days and 80% on off days?

 

[tzzhc4]

2 years? If my losses continue like this, my car will be a brick by September! :shock: I'm really, really hoping for a balancing uptick after charging gets done this morning. It's been 5 charges...I really should be due one.

You are right, another 3 bars down this morning. So yeah if this keeps up I will have a brick by mid-August.

100 charge on carwings: 87.9% on SOC meter, 247gids

I park outside during the day, covered if I can find it but seeing 7 bars for battery temp during Spring/Summer is typical. I will go ahead and start a Google document too.

 

[mwalsh]

Mike, I believe that you were at 5% capacity loss in April, and are down another 5% a month later. I could be wrong, but it would appear that one of your battery modules is going bad. We'll know soon enough.

One more thing: I remember you posting Gid numbers from your car last fall. Did you keep a log by any chance? I haven't seen anything between October and April on the forum. This would be helpful in figuring out when the decline started. Would you remember? There appears to be one instance of 8% lower charge in early October, when your car was less than a year old. That's pretty unusual from what I've seen. Did your Gid number always fluctuate this much?

How does your charging routine look like? 100% on work days and 80% on off days?

Relatively benign losses over the last 16 months. When I first got my Gidometer I was pulling numbers ranging from 94 to 98. It was sort of rare for me to get above 98, and even more rare to get 100.

I guess about a month ago I started seeing numbers in the 92 to 96 range more often than not. It didn't phase me too much until I got a random 87 about 3 weeks ago. But then things seemed to go back to the "new normal", so I didn't think anything of it. After all, we were told to expect some capacity loss, and I had seen some. It was when I began seeing low 90s consistently this week that I became more concerned, because that would mean 2-4% capacity loss in the first 8 months of ownership; a further 2-4% in the next 8 months; BUT a further 2% in just ONE month.

As of this morning I did get a bit of a bump. Not as much as I was rather hoping for, but I'm currently at 91.1 / 256 Gids / 393.5 v. It's a fairly cool morning here today, so I'm running the climate control to see if I can get a further bump before leaving for the office.

My charging routine? Yes, 100% when I need the car for work and then 80% as needed over the weekend, unless I've got something to do that I know will require a full charge. Usually one 80% charge will get me through a whole weekend unless we have plans.

 

[Stoaty]

You are right, another 3 bars down this morning. So yeah if this keeps up I will have a brick by mid-August.

100 charge on carwings: 87.9% on SOC meter, 247gids

How many gids do you get from an 80% charge?

 

[mwalsh]

How many gids do you get from an 80% charge?

I know this isn't directed at me, but I got 201 on my last 80% charge?

 

[mwalsh]

Something else I've noticed...my city consumption, which has always been poor compared to highway (I don't know why) is now simply attrocious. Fortunately I do very little city driving.