Hx dropping constantly!

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Well, Jim isn't wrong. After finishing the 100% charge on Sunday afternoon, I went for a short but energetic drive around the neighborhood and bled off 19 GIDs so it wouldn't be sitting 20 hours at 100%. Hx was 82.36 before that drive and 82.62 after. Monday my spousal critter worked at home, so I commuted with plenty of squirt/regenerate/squirt cycles, and am generally trying to drive NON-gently in non-eco/B. SOH went back up to 85% overnight on Sunday, and Hx is now back up to 83.54.

I don't know how we could tell if this is "real" or if it is just gaming the Hx algorithm, but it's more fun than driving like a granny. It also has amazingly little impact on my miles per kWh, which is a big plus for the Leaf. I feel guilty driving my Subaru with any verve since it just wastes gasoline pumping extra air though the engine then heating the brakes. At least the Leaf recaptures a fair amount of the excess kinetic energy.

I'm just worried all that torque is going to shred my almost-done tires. But I needed a good reason to get new ones before the rainy season(s) start anyway. Removing all the remaining tread by challenging the traction control should do it. ;)
 
...and back up even more this morning. SOH now back to 86% as when I first saw the car. I was driving fairly normally since spousal critter was in car, but still managed to get in some sprightly launches. I'm certainly happy with this. Of course, I don't know how much of this is driving style and how much is doing the deep cycle on the battery last weekend.

 
Sorry to say, I got a headache and whiplash from reading these posts of this new Leaf owner and his state of health stats... Dude, have your spousal critter take away your Leafspy module and have her throw it in the river. You obviously have a love of measuring things to the point that is not healthy for YOUR batteries... Stop with the Leafspy and just drive the car??

The SOH is not going to drop, just like you will not need a nursing home just because you got some grey hairs...
 
On my way to golf after work I pushed the Leaf, pulsing and regening in Eco >B mode there and back home. Mostly highway. Only went 42 miles but went from 91% to 32% SOC by the time I returned home. Will keep experimenting. Curious to see if the SOH % climbs. My understanding is LeafSpy only updates this periodically?

Making a 110-mile RT tomorrow where I will charge at my destination before returning home. Good opportunity to keep pushing.

pushing-leaf.jpg
 
Updating the spreadsheet above, my Hx has fallen to 97.1%, 63.29 AHr and 96% SOH. No amount of pulse driving will maintain my high of 103.57% Hx, 67.3 AHr and 100% SOH. Numbers keep falling.
 
I had time after work last Friday and decided to see if the car would let me juice the battery. I am able to L2 charge at work and left with 92% SOC. I had dropped to 93% SOH, 61.11 AHr, 94.02% HX. Sure enough the Hx numbers started to climb when I pulse drove. By the time I reached 32% SOC I was able to raise the Hx to 98.49%. A few hours later the car updated the AHr and SOH numbers to 64.25 and 98%.

I L2 charged the car at home the next morning and set out to see if the car would let me keep juicing the battery. There is a nice 10 mile stretch of 2-lane road near my house that is flat and lets me get the car up to 50-60mph then let off the accel pedal. I watch the energy regen screen. In B mode it hits .30. Once it drops below that I accel back to 50-60 mph trying to get at least 5-6 bubbles or max it out. Then let off and repeat the cycle. For each pulse cycle I got back .01 Hx. 100 cycles to get back 1% of Hx in general. I left that morning with 92% and kept pulse driving until I reached 32% where this trick stops working. After the car updated I reached 66.44, 100%, 101.95%. It looks like I could have kept going if I had not reached 32% SOC.

In the name of experimentation I tried again the next morning and the numbers just dropped.

When I reach the mid to low 90's SOH I'll see if it lets me juice again. Seems to work best after a fresh charge. Not sure if Eco > B works better than normal driving > B. In the meantime I'm going to drive more aggressively when possible to see if the rate of drop slows compared to last time.

My weekday commute is only 8 mile RT so I have little chance to push the car and weekends are hit/miss how much I drive. I'll just have to find the time to keep experimenting.

HTH.
 
so I have a 2015 down a bar (11920 miles)

soh = 85
hx = 76.75
ah = 53.05

I have driven evs for 15 years so I am light footed and careful. I think its a worthy experiment to see if I can get my bar back driving the hx way. But the real question is does higher hx and then the soh and ah going up translate to more range.

IE do we just have a sampling error making us show low/high.
 
Good question. All I can offer are these stats:

At 9,305 miles I was at 60.11, 91%, 92.28% (AHr, SOH, Hx).
100% charge was showing 260 GIDS 20.2 kWh remaining

at 11,065 miles 66.65, 100%, 102.34
100% charge was showing 284 GIDS and 22.0 kWh remaining

I'm back in free fall state. On the way home I drove 8 miles and watched the Hx value fall from 98.91 to 98.17. The car is around 50% SOC. I'm going to charge at work tomorrow and see if the numbers will climb on the way home with pulse driving. Past experience says no, but it will be a good test.
 
Better question is how long will you keep playing this game ;)

Stop worrying about it so much. The main things to avoid are:

  • High temperature charging
  • Keeping the pack idle at either low or high states of charge for a long period of time
  • Frequently cycling the pack charge between 80% and 100% SOC

If you avoid those bad habits, then everything else is pretty much out of your hands.

Obsessing over the pack health will ruin your enjoyment of the car.
 
alozzy said:
Better question is how long will you keep playing this game ;)
Stop worrying about it so much. The main things to avoid are:
  • High temperature charging
  • Keeping the pack idle at either low or high states of charge for a long period of time
  • Frequently cycling the pack charge between 80% and 100% SOC
If you avoid those bad habits, then everything else is pretty much out of your hands.
Obsessing over the pack health will ruin your enjoyment of the car.

I've followed your suggestions another other common wisdom since I purchased the car. By "Grandpa" driving I watched my battery SOH drop from 100% to 91%. If I can keep my battery SOH high and extend the useful life of the battery by changing driving habits, it's worth investigating to negate Nissan's inferior battery technology.
 
jim0266 said:
alozzy said:
Better question is how long will you keep playing this game ;)
Stop worrying about it so much. The main things to avoid are:
  • High temperature charging
  • Keeping the pack idle at either low or high states of charge for a long period of time
  • Frequently cycling the pack charge between 80% and 100% SOC
If you avoid those bad habits, then everything else is pretty much out of your hands.
Obsessing over the pack health will ruin your enjoyment of the car.

I've followed your suggestions another other common wisdom since I purchased the car. By "Grandpa" driving I watched my battery SOH drop from 100% to 91%. If I can keep my battery SOH high and extend the useful life of the battery by changing driving habits, it's worth investigating to negate Nissan's inferior battery technology.

So I am curious...
It has been about a year and 1/2 since this post... Still doing the pulsing thing? How's your battery holding up?
The main question I have is about range. Have you done any range test to confirm battery is indeed still healthy?

I'm going nuts over my battery stats dropping, mostly because I am concerned about loss of range, obviously.
I tried this pulsing thing a few times, but then stopped, realizing that it must be fooling the BMS, as there's no way it can be good for the battery.

But I am still curios.

Jim, if you're still around I am interested to hear how your battery is doing.

Cheers
 
jim0266 said:
alozzy said:
Better question is how long will you keep playing this game ;)
Stop worrying about it so much. The main things to avoid are:
  • High temperature charging
  • Keeping the pack idle at either low or high states of charge for a long period of time
  • Frequently cycling the pack charge between 80% and 100% SOC
If you avoid those bad habits, then everything else is pretty much out of your hands.
Obsessing over the pack health will ruin your enjoyment of the car.

I've followed your suggestions another other common wisdom since I purchased the car. By "Grandpa" driving I watched my battery SOH drop from 100% to 91%. If I can keep my battery SOH high and extend the useful life of the battery by changing driving habits, it's worth investigating to negate Nissan's inferior battery technology.

Complaining about "inferior battery charging" is like eating a steak at a restaurant and complaining they are bad the following week. You ate the steak by buying the car like all of us, and your issues are no different from everyone else's. We don't complain about it.

a) your concerns will not get you squat if you are trying to establish a paper trail to $$
b) As Alozzy stated, you need to stop obsessing about your battery because there ain't a honey diddly you can do about it. We are all getting older together, so let's all enjoy the ride.
c) As I mentioned in another post, you cannot interpret ANYTHING about small changes in the battery statistics.
 
By "Grandpa" driving I watched my battery SOH drop from 100% to 91%. If I can keep my battery SOH high and extend the useful life of the battery by changing driving habits, it's worth investigating to negate Nissan's inferior battery technology.

A lot to unpack here. You make a claim [“extend the useful life”] that is not backed up by your testing. I read all that you did with great interest, and what’s lacking is a definitive tie to a relationship between your driving approach and range. Until you can show a “before and after” test that proves your technique results in a positive impact on range, I am left with the opinion that this is “BMS Spoofing”.

Let me be clear: I totally respect the time and effort you have put into this and I commend you for your efforts - at a minimum you have raised some very interesting observations on the Leaf’s BMS system.
 
joeriv said:
By "Grandpa" driving I watched my battery SOH drop from 100% to 91%. If I can keep my battery SOH high and extend the useful life of the battery by changing driving habits, it's worth investigating to negate Nissan's inferior battery technology.

A lot to unpack here. You make a claim [“extend the useful life”] that is not backed up by your testing. I read all that you did with great interest, and what’s lacking is a definitive tie to a relationship between your driving approach and range. Until you can show a “before and after” test that proves your technique results in a positive impact on range, I am left with the opinion that this is “BMS Spoofing”.

Let me be clear: I totally respect the time and effort you have put into this and I commend you for your efforts - at a minimum you have raised some very interesting observations on the Leaf’s BMS system.


I concur and this Jim guy has not answered. I've asked him the following twice:

Jim, thanks for posting.
But I have a question. What is your range... if you charge to 100% and drive on a flat road with 55mph cruise how far can you go before low charge kicks in?
What is your miles per % SOC at 45mph, 55mph, 65mph
In other words has your pulse driving preserved the range ... stats are nice, but what about range, that's ultimately what matters.
Thanks!


twice No answer, he just dropped off the radar.
I've had my "used" Leaf now for just over 7 months in FL, and I noticed how battery capacity increases with higher battery temperature.
So I can only assume that this pulse driving causes a temporary increase in battery capacity as it increases batt temp. which in the long run will cause battery health to deteriorate.

My $0.02

Mr. Jim if you're still out there please provide some insight on your range. Gracias
 
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