Capacity vs Hx (Health)

[TonyWilliams]

If the xFaxtor can go up with gentle driving habits, perhaps
it is just an ADPF = Aggressive Driving Performance Factor,

It could be the holy grail of GuessOmeter performance?

[DaveEV]

Will my Ahrs drop over the next 3 weeks while Hlth/X rises, or will they both drop, as some have reported?

Beginning to get an answer to this question today--after only one day of driving post-update, AHr number dropped from 58.53 to 56.39, and Hfactor from 77.19% to 72.36%.

Don't be surprised, it will continue to drop rapidly until you get down to 54-55 Ah since you lost a bar recently.

It never tracked my capacity/SOH very well but the spread did increase. Before the update it reported 62.4 versus 69.5% SOH. Afterwards it is 51.5 versus 72.2% SOH.

Unfortunately I don't have any health data from before the update. Since the update I have noticed that regen is significantly more limited at 80% than it used to be (used to get 25+kW of regen in warm weather at 80%, now have to get down to 70% to get 25+kW of regen), it could be that the car uses the health rating to help determine max discharge/charge current in/out of the pack and now that health is more pessimistic, allowable regen is lower.

FWIW I'm currently at 55.70Ah / 70.63% Health, 12 CAP bars). A month ago I was at 56.25Ah / 72.00% Health.

[FalconFour]

That's why I wrote up that long couple posts on the last page. :/

Since I discovered "health", which does make sense as monitoring the internal resistance of the cells, I've been changing my driving habits quite a bit - doing less things that I know put strain on the battery. Since I've been gentle to the car, health has improved at a much more responsive rate than capacity, which is also slowly ticking upwards as well...

By "improved" do you mean the number has gone up or do you mean that it is dropping at a reduced rate?

Improving meaning that both numbers have gone up, but the Health seems like it's going up faster than Capacity as I've been changing my driving. I can say it's no longer appearing to trend downwards, but this is why I desperately would like to see a proper (*see attachment*) in the app. That would be key to really identifying what this data represents.

On a side note, I had the Leaf firmware update done a while before discovering the "Health" figure added to the latest version, so everything I know about Xfactor/H/etc is based on post-update info, nothing mixed between software versions. It's actually fluctuating up and down (even while driving! Slowly, for sure) with a slight upward trend now that I'm driving with more efficiency. I recall not too long ago that I was sitting at 68.86% and observing the mirrored pattern of numbers, so that's kind of my "milestone" marker - it's been down to 68.77% and up to 69.20% in the past week alone.

edit: OK, so I Googled "histogram" and discovered that I'm having a Vizzini moment with that word. Best example I can think of is the ubiquitous Task Manager histog... er... history graph. Is there a proper term for this? I honestly thought this was called a Histogram, but it turns out that a Histogram is a term for a chart of frequencies, not a history chart...

[ttweed]

Will my Ahrs drop over the next 3 weeks while Hlth/X rises, or will they both drop, as some have reported?

Beginning to get an answer to this question today--after only one day of driving post-update, AHr number dropped from 58.53 to 56.39, and Hfactor from 77.19% to 72.36%.

Don't be surprised, it will continue to drop rapidly until you get down to 54-55 Ah since you lost a bar recently.

Rapidly is right! It is already back down to 54.6 AHr today, a week after the update! The troubling part is that Hfactor is down to 67.85%, which is over 10% below what it was pre-update!

TT

[garygid]

All the worry over these "unknown-meaning" values is likely
part of the reason why they are not displayed on the dash.

Observing the voltages of the cell-pairs, and the GIDs, give
you most of the important information about the battery.
Of course, understanding the observations is non-trivial.

[TomT]

I tried to get more info on the Health/XFactor/Whatever value from Craig at our Phoenix meeting but didn't glean anything that really shed any more light on it... He did say that it is more complicated than some realize...

Since the update I have noticed that regen is significantly more limited at 80% than it used to be (used to get 25+kW of regen in warm weather at 80%, now have to get down to 70% to get 25+kW of regen), it could be that the car uses the health rating to help determine max discharge/charge current in/out of the pack and now that health is more pessimistic, allowable regen is lower.

[DaveinOlyWA]

ok; late to the discussion and not willing to read the 10 pages before it so is there a consensus of what Health is?

also a side question; is what the LEAF Spy is getting before or after the BMS?

had a thought that the gentle ups and downs my car is reporting in both ahr and Health tells me that something is filtering it and averaging the results over a set time period. This accounts for the somewhat slow reactions to changes in weather, etc.

If that is the case, then its possible that some sort of equation is being applied to the Health number based on driving history?

[GregH]

Since I'm still on the pre-P3227 SW I can't say definitively.. but it seems like both Ah Capacity and Hx track UP just a bit when the temps are in the 19-23C range and down a bit when in the 25-30C range.. ie, high edge of 5TB is good and low edge of 6TB (or higher) is bad.. It doesn't update at the end of charge, but seems to updated while driving even if only every hour or so (?) In the last month my capacity has gone from 59.0793Ah (87.70Hx) to 61.0014Ah (91.41Hx) due to the cooler temps. A brief warm spell a few days ago brought them both down just a tad.

[TomT]

Perhaps not surprising since we were told that better temperature compensation was part of the P3227 upgrade...

Since I'm still on the pre-P3227 SW I can't say definitively.. but it seems like both Ah Capacity and Hx track UP just a bit when the temps are in the 19-23C range and down a bit when in the 25-30C range.

[stjohnh]

ok; late to the discussion and not willing to read the 10 pages before it so is there a consensus of what Health is?

I read the 10 pages, which confirmed what I had thought. YES there is a consensus !!

It is an unknown digital number, possibly related the Leaf you are driving !!!

AND !! ta da..... Nissan reps have said "it is more complicated than some realize!!"

So there you have the definitive response to what "Health" is.

Hope that helps.