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Re: Charge a little each day, or longer charges every few days?

Posted: Sun Jul 22, 2018 7:46 pm
by cwerdna
^^^
I don't care about the percentages in Leaf Spy. What's the denominator?

IIRC, LBW sounds at about 49 gid and VLBW at about 24 gid on 24 kWh Leafs.

Re: Charge a little each day, or longer charges every few days?

Posted: Sun Jul 22, 2018 8:23 pm
by be236
What are the various "low battery indicators?"

Let me list them and you guys can correct me. I'm on Nissan 2017.

On the main cluster display:

1. "low battery warning."
2. "three dashes where the GOM is." (what is the last GOM miles number before it goes to dashes?)
3. "very low battery warning."
4. "turtle icon mode"

-Andrew

Re: Charge a little each day, or longer charges every few days?

Posted: Sun Jul 22, 2018 9:47 pm
by LeftieBiker
Silverfish wrote:
LeftieBiker wrote: This is a good strategy. However, you shouldn't be getting any kind of "low battery warning" at 30%, unless you have a severely degraded battery. More like 18-20%.
In the two months I've had the car, I always get a low battery warning at 16-17 miles on the guess-o-meter, which registers as between 29% and 32% in LeafSpy. I did wonder about that.

How would I know if I had a severely degraded battery? The range is pretty consistent at about 70-75 miles on the GoM at 100% charge, and 55-60 miles at 80% charge, depending on how much freeway driving I've been doing. On 100% charge, I can generally drive 50-55 miles before hitting the low battery warning. On an 80% charge, it's about 30-35.

It's a 2013 SV with about 53,700 miles and 11 bars. SOH is hovering between 76% and 77%, so I'm surprised it's not yet at 10 bars. Do all those numbers not add up right? Maybe there's a way to reset the % at which the LBW sounds, and the previous owner did? I'd be happy to drive it down to 20%, just been nervous because of the warning.

Thanks.
The Low Battery warning does come at higher and higher percentages as the battery loses capacity, so a pack nearing 9 bars might show it at about 30%. I would define ~9 bars as somewhere between "substantially degraded" and "severely degraded." How many miles of remaining range the Guess 'O Meter gives depends on several variables, so while it might be consistent for you, it doesn't make for an apples to apples comparison with other Leafs.

Re: Charge a little each day, or longer charges every few days?

Posted: Sun Jul 22, 2018 10:11 pm
by Silverfish
Thanks, folks.
cwerdna wrote:^^^
I don't care about the percentages in Leaf Spy. What's the denominator?

IIRC, LBW sounds at about 49 gid and VLBW at about 24 gid on 24 kWh Leafs.
I'm not sure which denominator you mean.

Some stats on a time I hit LBW a couple of weeks ago:

GIDs: 47 (there's also a 16.7% value that might correlate with GIDs)
SOC: 28.9%
3.6 kWh remaining
AHr: 50.69
SOH: 77.5
HX: 70.33
GoM: 15

Does that answer your question? I'm not really sure of the difference between GIDs and SOC; I've mostly been tracking SOC. Should I track GIDs too?

I've only ever hit LBW, never VLBW or turtle mode. I generally hit LBW just a couple of miles from home, partially because I'm rarely more than a couple of miles from home. :)

ETA: There's also a DTE value for these LBW readings that looks like it's at about 13%.

Re: Charge a little each day, or longer charges every few days?

Posted: Sun Jul 22, 2018 11:42 pm
by cwerdna
Silverfish wrote:Thanks, folks.
cwerdna wrote:^^^
I don't care about the percentages in Leaf Spy. What's the denominator?

IIRC, LBW sounds at about 49 gid and VLBW at about 24 gid on 24 kWh Leafs.
I'm not sure which denominator you mean.
I don't mean to insult your intelligence but let's take a step back:
numerator / denominator = some result that you can convert to a % if you multiply by 100
49 / 100 = 0.49 = 49%

If see SOC % of 28.9% and in an earlier post, you said "which registers as between 29% and 32% in LeafSpy", what is the numerator and what is the denominator to arrive at this? Of what use is this %?

You said "GIDs: 47 (there's also a 16.7% value that might correlate with GIDs)". Why would I care about 16.7%? What's the numerator and denominator here? Do you see why I don't care? I'd rather just look at the actual gid value.

We already have at least 3 percentages that vary with the state of the charge of the battery: SOC % in Leaf Spy, gid % in Leaf Spy and the dash display's % SoC (which was developed by Nissan independently of Leaf Spy). I only pay attention to the dash display's % SoC and raw gid number. The other two percentages I don't care about.

Re: Charge a little each day, or longer charges every few days?

Posted: Mon Jul 23, 2018 3:15 am
by SageBrush
Regarding VLB warning at a LeafSpy reported SoC of 30%:

LeafSpy uses a 0-100% scale that includes the reserved (unusable) capacities at the top and bottom of the battery. I don't know exactly how much is at the bottom but if it is ~ 1 kWh, that is equal to ~ 4.5% of a new battery and about 3 Ahr. The LEAF uses a SoC scale from 0 - 100% that ignores the unusable buffers at the top and bottom of the battery.

There is about 11 Ahr usable at VLB
LeafSpy measures 14 Ahr remaining by including the bottom buffer

OP's battery has about 50 Ahr usable, so at VLB LeafSpy measures a SoC of (11+3)/(50+3) = 26.4%

Re: Charge a little each day, or longer charges every few days?

Posted: Mon Jul 23, 2018 3:59 am
by LeftieBiker
He's talking about the Low Battery Warning, not the Very Low Battery Warning, which he has never reached.

Re: Charge a little each day, or longer charges every few days?

Posted: Mon Jul 23, 2018 5:40 am
by SageBrush
My mistake, I meant LBW

Re: Charge a little each day, or longer charges every few days?

Posted: Mon Jul 23, 2018 7:53 am
by Silverfish
cwerdna wrote:
Silverfish wrote:Thanks, folks.
cwerdna wrote:^^^
I don't care about the percentages in Leaf Spy. What's the denominator?

IIRC, LBW sounds at about 49 gid and VLBW at about 24 gid on 24 kWh Leafs.
I'm not sure which denominator you mean.
I don't mean to insult your intelligence but let's take a step back:
numerator / denominator = some result that you can convert to a % if you multiply by 100
49 / 100 = 0.49 = 49%

If see SOC % of 28.9% and in an earlier post, you said "which registers as between 29% and 32% in LeafSpy", what is the numerator and what is the denominator to arrive at this? Of what use is this %?

You said "GIDs: 47 (there's also a 16.7% value that might correlate with GIDs)". Why would I care about 16.7%? What's the numerator and denominator here? Do you see why I don't care? I'd rather just look at the actual gid value.

We already have at least 3 percentages that vary with the state of the charge of the battery: SOC % in Leaf Spy, gid % in Leaf Spy and the dash display's % SoC (which was developed by Nissan independently of Leaf Spy). I only pay attention to the dash display's % SoC and raw gid number. The other two percentages I don't care about.
I don't know the numbers that the Leaf or LeafSpy uses to arrive at its percentages, which is why I said I didn't know which denominator you meant. All I see are the numbers in the LeafSpy display pages; most of it is Greek to me. Honestly I'm not sure what use the GID value is either, or how it's used in calculating any of the percentages. I was just providing the data I saw, hoping that that info contained the answer to your question.

So what does the GID number mean?

Re: Charge a little each day, or longer charges every few days?

Posted: Mon Jul 23, 2018 12:12 pm
by jim0266
See my post about living at a low SOC and pulse driving to best protect your battery:

http://mynissanleaf.com/viewtopic.php?f=27&t=26229