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Re: Hx dropping constantly!

Posted: Thu Jun 08, 2017 7:57 am
by BuckMkII
LeftieBiker wrote: The best time to check it is probably right after a 100% charge. After an 80% charge is likely NOT the best time. The charge lights behave as if there is equalization after an 80% charge, but that may not be what actually happens.
Right. When I re-read your post above after making mine, I figured I was doing it wrong. If I get down to VLBW on Saturday evening, I may have to either use the ICEs on Sunday morning while it reaches 100%, or if I decide to go into work for a couple of hours, interrupt the L1 home charge and finish it up on the L2 at work.

Would an interruption in the charge cycle and a short drive (7 miles) before going up to 100% have any effect on the battery magic?

Re: Hx dropping constantly!

Posted: Thu Jun 08, 2017 12:00 pm
by jim0266
I thought this Facebook discusson on the "My Nissan Leaf Owner" group is worth sharing.

This Leaf owner has a 2014 Leaf with 25.3K miles and still showing 100% SOH via LeasSpy. Our Back and forth:

Iniitial Response to keeping SOH health high: Drive faster. Accelerate faster and regenerate as much as you can in B mode. Forget about hypermiles and do not drive slowly and very gentle. This slowliness is killing your battery.

Q: What MY is your Leaf?

A: First Registered December 2014

Q: Thanks. Can you give a few more details on how you drive and charge your Leaf? When accelerating do you try to hit 4 or 5 power bubbles or as many as possible? When I purchased by 14 Leaf a few months ago it had 8,750 miles, SOH 100%, AHr 67.36 and Hx 104.28%. Today at 10,392 miles I'm at 92% SOH, AHr 60.34 and Hx 92.49%. I've been driving gently 85% of the time. Going to push the car the next few months and see where my numbers go. I assumed age degradation was at play. I also do not have QC on my car.

A: When i accelerate my aim is 5+ power dots, it only takes few seconds to get up to 30mph.

There is a bunch of info you need to know.
You have the HX value, which influences your SOH and AHr.

I found out that you can push and maintain HX value up and above 100% by short fast accelerations and power regeneration in very next second.

I keep lot of distance between me and vehicle in front of me. I accelerate fast 5-7 bubbles and next second lift the throttle and regenerate, best results in B mode ECO.

Also when first in line at traffic lights i don't miss a race, even when I’m the only car on the road 8-)
The easiest way to litteraly push up your HX is driving on highways 60mph accelerate full throttle up to 65mph, release throttle for regeneration in B mode. When it slows down to 60mph repeat. If you use leaf spy/happy leaf you'll see HX going up with every acceleration.

Battery must be at above 33% on dashboard, from this charge and down your battery values will freeze, no matter what you do they wont change. Usually from this state of charge i drive very gentle to get the maximum range for my remaining 33%.

You may want to aply this treatment immediately after DC charging, its easier because even the 3-4 power accelerations will make an improvement. When i charge with my 10A evse (~2.4kwh) i find it a little bit difficult to keep HX up as i need to be very harsh with the car.
Best time to work out your HX is immediately after DC charging. Push it up as much as you can with every DC charging and try keep an active driving style for the rest of the time, drive slow and gentle below 33% charge as this doesn't count on BSM.

Sometimes i charge every day on DC and my HX goes up to 102-103% without trying too much. I'm checking my charge on leaf spy at least once a day, when my HX is 99% I'm heading for my nearest DC charger.

Your SOH will follow HX value, not instantaneous because it's updating only couple of times a day or so. Also AHr is improving accordingly.

My response: Thanks for the detailed information. I'm going to drive your way for the next few months and see where my numbers go. It might be harder since I can only charge L2, but I never L1 charge. My employer provides L2 chargers. Free driving! My commute and other driving needs are not long range so I seldom need to fret about my SOC. Have to admit the Leaf is a different beast when you push it!

His response: It needs fresh charging. I charged once DC on Friday afternoon and i used my car for about 15 miles over the weekend. Monday morning i barely managed to maintain HX by accelerating really fast. Somehow this chemistry works better immediately after charge.

Re: Hx dropping constantly!

Posted: Thu Jun 08, 2017 12:14 pm
by LeftieBiker
I suspect that if he were to start driving normally, his SOH and Hx would drop to a more normal reading. I think he's just manipulating the car to provide higher readings than normal, by stressing the pack to keep resistance from creeping up. I could be mistaken. Maybe he really is preventing it from building up.

Re: Hx dropping constantly!

Posted: Thu Jun 08, 2017 2:39 pm
by BuckMkII
Oh, goody! An excuse to drive for fun, not for 'fficiency! Life is too short to drive in Eco (and so is my commute).

The only problem is that if I drive in non-Eco/B with a heavy foot to show off the Leaf's off-the-line acceleration and keep the battery warm, my spousal critter is going to be yelling at me to stop surging and making her car-sick. Or she'll just start punching the dashboard.

Re: Hx dropping constantly!

Posted: Thu Jun 08, 2017 7:14 pm
by jim0266

LeafSpy report from when I left work and returned home. Driving in Eco & B-mode with as much acceleration as the traffic allowed with regen. Nice little push in Hx. As I've tracked my battery health I've also noted LeafSpy does not accurately track charges. LS has reported 417 charges since May 28th. How much can I get back or am I stuck in the 91-93% range but keep it there for a good while by driving this way? Time and testing will tell...

Re: Hx dropping constantly!

Posted: Fri Jun 09, 2017 12:26 am
by cwerdna
BuckMkII wrote:
On weekdays, it's usually just charged once at work (almost always with a midnight to midnight 80% timer Mon thru Thurs) and that's it. On some days, I remotely trigger it to go to 100% about 1-2 hours before I leave. On virtually all weekdays, I don't
Why a midnight-to-midnight timer? I've given only the briefest glance at the timer issue. I'd have guessed that would make it wait until x hours before midnight to start charging (where x is the calculated time to charge), but unless you work nights that must be wrong!
It's for the reason at ... 53#p336053.

On most days of charging at work, I just use the above trick. If I need to go to 100%, when Carwings/NissanConnect is working, I just remotely sent a start charging command via their iOS app and it'll continue from that point until 100% or unplug.

I time my sending of that command to be between 45 minutes and 2 hours 10 minutes of when I need to leave. If I know I really want to be totally fully and battery probably balanced better, I send it about 2:10 before. If I just need more than 80% but don't really need the full 100%, balancing and all, I send it 45 mins to 1 hour before I leave. About 1 hour on my car is enough for the car to start tapering and ramping down charge rate.

If I use the 80% long-life mode setting, I'm pretty sure that sending the above command makes it only go to 80%, so it stops within a few minutes at 80%.

Re: Hx dropping constantly!

Posted: Fri Jun 09, 2017 12:45 pm
by BuckMkII
Hx has been loitering around 82.4 for the last couple of days, so maybe it has stopped declining. Either way, I expect to lose the 12th bar any day now. :cry:

I found the previous owner's name by checking the Bluetooth phone pairing list, and a little Google stalking shows that they own a home near the Safeway at Highway 84 and Newark Rd, which is good (near the bay; not in Livermore!) but their work phone is at a state agency headquartered in Sacramento, which is not so great.

However, looking in the Nav menu of previous destinations going back to Fall 2013, all that I could recognize were in or around San Jose, so I suspect they were a field agent working in the South Bay and were not hauling off to Sacto every day, which would seem impossible without a QC.

It's amazing how many electronic Easter eggs you can find in a car with lots of built-in electronics!

Maybe I will politely ask via their email if the car still had 12 bars when they last saw it, but I'm at the moment tentatively betting against a highly abusive temperature history or a BMS reset.

Re: Hx dropping constantly!

Posted: Fri Jun 09, 2017 7:31 pm
by GerryAZ
You have a ways to go before you lose the first bar (SOH needs to get down to 85% before first bar drops). Drive it aggressively and your numbers will improve (QC once in a while also helps). You have 417 L2 charge counts since the car was new (not since you started using Leaf Spy).

Edited 6/11:
Oops, I confused 2 posts. The 2400 L1/L2 charges likely means that charge and climate control timers were used extensively (using both can give 3 charge counts per charge). Your SOH of 85% is close to the threshold for loss of first capacity bar, but there is time lag and your usage pattern may delay the loss.

Re: Hx dropping constantly!

Posted: Fri Jun 09, 2017 10:10 pm
by BuckMkII
SOH briefly dipped to 84% on Tuesday, went back to 85%, then returned to 84% early Thursday, where it's stayed. Hx is now 82.29.

I should get down to VLBW Saturday afternoon, then will do a 100% L1 overnight.

Re: Hx dropping constantly!

Posted: Sat Jun 10, 2017 4:00 pm
by jim0266
Made an 80-mile RT run mostly on the highway today driving in Eco-B mode. Left with Hx at 93.88. Whenever I safely could, I would accel as fast as I could and coasted for the max regen. At the end of my trip the Hx increased to 94.80.