Battery health at 143,000 miles

[Zardoz]

you can just click the link to see the graphs anyway. i paste them there just for ease / super lazy people

I knew that at one point.

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[awp0]

The day I purchased the car, it was 100%

I'm sure that was bogus and the algorithm just hadn't had time to populate the equation.

I didn't really look at it again for a few weeks and it had dropped to 94%

A couple of months later it hit 92% and I decided to follow Mach-Lee's suggestion of using L2 charging and giving the BMS an opportunity to "balance" the pack.

Sure enough I gained a couple of % the first time.
I waited about a month and did the procedure again. Gained another %.

The third attempt gained yet another % and that's the screenshot of 96%.

Honestly, I still don't care as much about the SOH PID value as I do about how well balanced the battery pack is as it gets to the lower half of the SOC. To me that's far more indicative of how "healthy" a battery is since THAT is what determines the real range that the battery can provide to the vehicle.

I built a PID gauge that summarizes the balance of the battery pack at a glance. It has been interesting to watch the 100% L2 charging procedure narrow the variation of SOC between cells to basically NO variation, and watch the SOH value climb simultaneously.

It's the cluster of green pids/gauges below. (red arrow)

4Pids =
HVB minimum module voltage
HVB average module voltage
HVB variation SOC between modules
HVB variation voltage <> Batt modules

This is super interesting. But when it was at 94% the variation was within .01v right? What was the variation at 92%? I'm just trying to understand if you're able to observe the improvement in variation, and if it's as subtle as going from .01 to .00? Also, what actually is the L2 balancing procedure? How low do you let the battery go, and how long do you leave it on the charger after it reaches 100%? Is there a recommended charging amperage for this? Thanks!

 

[Byrus]

The app Snakebitten mentioned and an OBD2 reader like the one below. There are cheaper options, bu this one is known good for forscan.
https://www.amazon.com/dp/B07JFRFJG6

Thanks.

 

[Nikos]

Took my E-Pony into dealer for recall issues. I asked dealer to test for battery degradation. It is at 89.5%.

My 2021 Pony has 143,000 miles. That battery degradation is much better than I expected. For most people, that mileage is 10 years of driving.

I charged the car nightly up to 90%. Since new, I have used fast charging less than 20 times.

So I guess the car will last to 1.4 millions miles before battery degrades to 0%. Haa haaaa.

Excellent. That is some very useful info for those who wonder what happens after the warranty on the battery expires. Confidence is high.
Thank you for sharing.

 

[Nikos]

App called Carscanner

I have the Carscanner app and setup. I need to look into that same page myself and look at that.
Thanks.

 

[CTZ]

Mine's 92% at 26K miles. I'm hoping this is because I need calibration but I bought it used so I don't know how it was treated before I bought it. Seems low.

 

[Blue highway]

I’ve tried that in the past but will give it another try. I did dial down my L2 charger from 50 to 30 amps since then and will try again. I usually run it down to around 20-30% and then back up to 80. I’m retired so have shorter daily drives and charge about every 5 days. In the past I have seemed to loose the most on long trips between Michigan and Florida. Perhaps that unbalances the cells? Will try what you suggest.

The Ford Battery Control Module doesn't do balancing till you charge it up to 90% or greater. (almost all BCMs work this way, the balancing is right at the top of the pack). Soooo.... charge it to 90% or greater a few times and give it a chance to balance the pack. Balancing takes some time so leave it at 90 for a few hours as opposed to driving it right away.

You don't need to do this very often.

 

[Trick.Mach-E]

The day I purchased the car, it was 100%

I'm sure that was bogus and the algorithm just hadn't had time to populate the equation.

I didn't really look at it again for a few weeks and it had dropped to 94%

A couple of months later it hit 92% and I decided to follow Mach-Lee's suggestion of using L2 charging and giving the BMS an opportunity to "balance" the pack.

Sure enough I gained a couple of % the first time.
I waited about a month and did the procedure again. Gained another %.

The third attempt gained yet another % and that's the screenshot of 96%.

Honestly, I still don't care as much about the SOH PID value as I do about how well balanced the battery pack is as it gets to the lower half of the SOC. To me that's far more indicative of how "healthy" a battery is since THAT is what determines the real range that the battery can provide to the vehicle.

I built a PID gauge that summarizes the balance of the battery pack at a glance. It has been interesting to watch the 100% L2 charging procedure narrow the variation of SOC between cells to basically NO variation, and watch the SOH value climb simultaneously.

It's the cluster of green pids/gauges below. (red arrow)

4Pids =
HVB minimum module voltage
HVB average module voltage
HVB variation SOC between modules
HVB variation voltage <> Batt modules

I was not aware of Mach-Lee's method to balance the battery pack but I stumbled up a SOH change that was interesting to me. The battery on our FE (46,000 miles) was in the 91.5% to 93% range when I submitted my SOH to the thread tracking it. At the time I submitted my SOH we were at 92%...

Then my wife did several daily 150+ mile trips where she started out with 100% each day and ended in the 35-40% range. The SOH jumped to 93% after her trips. I am going to try this a few more times over the next month and see if I can get the SOH to go higher...

 

[Snakebitten]

Because of the recent posts in this thread, I ran a "balancing L2 session" last night just to see if I could get another kick upwards on the SOH PID in car scanner. But this morning it was still 96%. Which I'm not unhappy about at all, just to be clear.

Still, that single value isn't what I would be most concerned with. On the same Carscanner dashboard are what I believe are the REAL indicators of the health of the battery.

I say that because of the deep dive into battery pack health that the nerdiest Leaf owners took me through as an EV newbie.

From my understanding, which is NOT an expert level, the typical EV battery management system will automatically protect the weakest cell/module in the battery pack. So if there IS a cell that has degraded at a higher rate than the other cells in the battery pack, that weak cell(s) will end up being the determining factor in the range of the vehicle.

Or put another way, a well "balanced" battery pack IS a healthier battery pack because the BMS can let the vehicle use the "average" energy level of the battery pack rather than have the weakest cell's voltage be the available energy determiner.

And on the Leaf specifically, the lower the overall SOC of the battery pack, the more variation between the voltage of each cell.

In the screen shot above, the variation between the cell's voltage is being reported as 1/100 V

That's a beautiful feeling for a Leaf owner, I can assure you! ???
Admittedly the screenshot was taken at a very high overall SOC of the battery pack, so it COULD be a little misleading. What you are desiring is a similar very small deviation in voltage or % between the minimum cell and the average, but when the SOC is nearer the bottom end of available energy. If the cells are still "balanced" when the SOC is 10%, you can feel very good the SOH of your battery whether it says 92% or 98%.

At least that's how I understand it.

Although nobody really knows the algorithm Ford is using to arrive at the SOH PID value, I can almost guarantee you that the highlighted PIDs above regarding variation of voltage between the cells ARE the most influential in the SOH algorithm.

I accept the fact that the cells will slowly degrade. Doesn't really bother me. I just want them to degrade at the same rate! Staying balanced. Which makes the entire battery pack available for energy withdrawal.

 

[Adventureboy]

I am curious if the OP does a top balance, where SOH will land.

 

[Snakebitten]

This is super interesting. But when it was at 94% the variation was within .01v right? What was the variation at 92%? I'm just trying to understand if you're able to observe the improvement in variation, and if it's as subtle as going from .01 to .00? Also, what actually is the L2 balancing procedure? How low do you let the battery go, and how long do you leave it on the charger after it reaches 100%? Is there a recommended charging amperage for this? Thanks!

That variation of .01V was momentary. The screenshot is static, of course. Sometimes the variation is 0V. But it can fluctuate as you are driving, especially as the SOC gets low(er).

On a Nissan Leaf, notorious for not having any kind of active thermal management (designed 14 years ago. Pre-Tesla even), you would want the variation to be less than 400milivolts ? as you got into the lower range of SOC. Say below 30%

The variation on a good Leaf battery pack might be 6-7 millivolts at 90% SOC. And then increase to 20-30mv at 30% SOC.

As the battery packs degraded, the variation could get in the 100's of mv. You'd be driving along at 28% SOC and if you hit an incline or punched it, your SOC could drop by 10% in the blink of an eye as the BMS intervened to protect the cell or cells that weren't stable at the lower voltage range.

For those folks on the road heading to a destination that needed the whole 30% SOC? Talk about range anxiety losing 20 miles in 1 second. ??

We are spoiled with the excellent BMS and balanced battery packs in these much more advanced EV's than yesterdecade.

 

[awp0]

That variation of .01V was momentary. The screenshot is static, of course. Sometimes the variation is 0V. But it can fluctuate as you are driving, especially as the SOC gets low(er).

On a Nissan Leaf, notorious for not having any kind of active thermal management (designed 14 years ago. Pre-Tesla even), you would want the variation to be less than 400milivolts ? as you got into the lower range of SOC. Say below 30%

The variation on a good Leaf battery pack might be 6-7 millivolts at 90% SOC. And then increase to 20-30mv at 30% SOC.

As the battery packs degraded, the variation could get in the 100's of mv. You'd be driving along at 28% SOC and if you hit an incline or punched it, your SOC could drop by 10% in the blink of an eye as the BMS intervened to protect the cell or cells that weren't stable at the lower voltage range.

For those folks on the road heading to a destination that needed the whole 30% SOC? Talk about range anxiety losing 20 miles in 1 second. ??

We are spoiled with the excellent BMS and balanced battery packs in these much more advanced EV's than yesterdecade.

Great information. Thank you! I have an electric skateboard and I'm loosely familiar with battery balancing and BMS protections, so this does make a lot of sense.

 

[Snakebitten]

Great information. Thank you! I have an electric skateboard and I'm loosely familiar with battery balancing and BMS protections, so this does make a lot of sense.

Hey there now!

I recently broke my femur, resulting in an artificial hip, when I naively laced up some roller skates to skate with my best friend. (6 year old granddaughter)

I've recovered pretty much, but I now know I'm too old to fall down. Which I was completely unaware of 3 months ago. ?

So.........I have been considering...... You guessed it. ?

What’s the sweet spot? Just before you start getting a reduced return on the additional co$t of purchase?

Just a nice smooth 30 minutes of actual ride time between charges, with an emphasis on old geezer stability.

 

[awp0]

Hey there now!

I recently broke my femur, resulting in an artificial hip, when I naively laced up some roller skates to skate with my best friend. (6 year old granddaughter)

I've recovered pretty much, but I now know I'm too old to fall down. Which I was completely unaware of 3 months ago. ?

So.........I have been considering...... You guessed it. ?

What’s the sweet spot? Just before you start getting a reduced return on the additional co$t of purchase?

Just a nice smooth 30 minutes of actual ride time between charges, with an emphasis on old geezer stability.

Well, as someone who's recovering from a separated shoulder on the thing, I would recommend AGAINST buying a OneWheel, which is a special sort of self-balancing skateboard that will throw you onto the ground under a number of conditions (pushing it too hard, failed electronics, overcharge, and of course a battery problem like imbalance combined with too low SOC).

 

[Snakebitten]

Oh heck no! Anything with the words one wheel in it?

Good to hear you survived.

Wheels come in pairs, in my way of thinking.

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