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Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Sun Nov 26, 2017 9:40 am
by DaveinOlyWA
Ok, the REALITY is that the loss of regen is a choice of Nissan programmers, not any issue with the battery itself. So this talk of resistance doing this and that is complete utter nonsensical BS. It is this reason why I think you have a legitimate claim for a dangerous vehicle. Its not worn out. Its simply does not have a programming that safely addresses declining battery capacity.

If the car can charge, it can also regen. On the flipside; in "any" car, no one goes to the manufacturer to get a good deal. But for whatever reason, the aftermarket has simply not materialized. Part of that is simply demand. There isn't enough. A lot of LEAFers simply gave up, got rid of the car for whatever price they could get for it and basically someone got a great deal... it just wasn't the original owner.

So replacing the battery at any cost will give you a pack that will likely last longer but does not resolve the root issue and that is the programming. It simply delays the time at which the car becomes dangerous again.

Why was this done in the first place? Nissan's way of saying the car is done, but a new one from us? Don't even say Nissan did it to help prolong the pack. that ship has already sailed. The reality is this requires introducing a completely different line of reasoning.

Gassers can downshift. Our downshift is regen. Without it, we are screwed.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Sun Nov 26, 2017 1:02 pm
by Yogi62
Is it possible that the regen circuitry is different from the charge circuitry and has a different duty cycle profile?

I don't have enough steep hills nearby to try what a 5 to 10 minute regen run, although in the past I had plans to try to get to the top of Mt Washington and charging on the way down. Anyone from colorado try Pikes Peek yet?

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Sun Nov 26, 2017 8:54 pm
by DaveEV
abasile wrote:it's perfectly reasonable for us to expect some minimal standard of safety performance, particularly during the 8 year / 100k mile battery warranty period.
There one important performance spec that also degrades along with the battery: Efficiency. Without regen, you lose significant efficiency whenever you have to slow for a stop, unless you are extra careful and give yourself plenty of room to slow down.

I really wonder how the EPA efficiency specs compare with a new battery compared to an old one, and if the EPA cares that cars within their warranty period can lose a significant amount of efficiency.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 12:00 am
by SageBrush
Good Luck, Abasille.

Perhaps your success will be a back door to warranty replacement for the entire group of owners past 5 years with a degraded battery.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 11:00 am
by abasile
I have a case number with Nissan's "EV hotline" and an appointment with the dealer down the hill. I intend to document my drive down the mountain, in terms of the braking behavior and my exact stops to let the brakes cool, and present this to the dealer.
SageBrush wrote:Perhaps your success will be a back door to warranty replacement for the entire group of owners past 5 years with a degraded battery.
That's one potential outcome. The bottom line is that Nissan has sold a vehicle with inadequate braking performance for the range of legitimate use cases in North America. If I were running Nissan, I'd be considering both hardware and software fixes.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 3:01 pm
by vrwl
abasile wrote:I have a case number with Nissan's "EV hotline" and an appointment with the dealer down the hill. I intend to document my drive down the mountain, in terms of the braking behavior and my exact stops to let the brakes cool, and present this to the dealer.

That's one potential outcome. The bottom line is that Nissan has sold a vehicle with inadequate braking performance for the range of legitimate use cases in North America. If I were running Nissan, I'd be considering both hardware and software fixes.
I will be following your posts about this. Just last week, I noticed that my regen was completely unavailable until I had 9 miles left in my current charge. Prior to that, no regenerative braking was occurring whatsoever. I do think the thoughts about colder air temps are valid, because I did not see this extreme level of loss of regen until it got colder outside. I’ve always had a problem with regen after the P337 software update, but NO REGEN available until I was down to my final two bars of current charge? This is insane. So please continue to post any updates, I’ll be interested to see what happens. I also live in a mountainous area, the Poconos of PA, although not quite the elevation you have in CA.

I have a 2011 with 34,000 miles on it and two capacity bars have been lost, although I think a 3rd one will be dropping soon.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 3:11 pm
by RegGuheert
DaveinOlyWA wrote:Ok, the REALITY is that the loss of regen is a choice of Nissan programmers, not any issue with the battery itself.
I agree with you, Dave. Regeneration should have an ABSOLUTE MINIMUM power level equal to the charging rate which would occur when you plug the car into an EVSE. In my case, that is 3.3 kW. Their software algorithms should then add the power draw of the climate-control system to that number to find the lowest level of regeneration that should be used at a given time.

It's pretty ridiculous to EVER set it to zero unless the battery is full or the temperature of the battery is below about 0 degrees Fahrenheit.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 5:23 pm
by abasile
drees wrote:There one important performance spec that also degrades along with the battery: Efficiency. Without regen, you lose significant efficiency whenever you have to slow for a stop, unless you are extra careful and give yourself plenty of room to slow down.
On my way down the mountain today, I ran the cabin heater at a continuous 3 kW or so. Owing to the fact that there was scarcely any regen available (4 temperature bars and less than 80% charge), the LEAF reached the bottom of the 4900' descent with less charge than I started with. Even at about 50% SOC (six battery bars) near the base of the mountain, the available regen was zero or close to it. I had to make two long stops to cool the brakes, thus doubling the duration of the drive. Even still, the brakes smelled and some shuddering occurred.
drees wrote:I really wonder how the EPA efficiency specs compare with a new battery compared to an old one, and if the EPA cares that cars within their warranty period can lose a significant amount of efficiency.
I doubt the EPA cares a great deal. Gasoline cars also lose efficiency with time, though not this dramatically.

The dealer representative who took my key fob did note on the paperwork that the car can't be driven down the mountain (that is, not in any "normal" fashion) due to bad regenerative braking. He seemed attentive to my concerns and was sympathetic when I explained that this is a safety issue and that regenerative braking is supported by the lithium-ion battery which remains under warranty for defects. We'll see what the LEAF tech says.

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 5:49 pm
by SageBrush
abasile wrote:I have a case number with Nissan's "EV hotline" and an appointment with the dealer down the hill. I intend to document my drive down the mountain, in terms of the braking behavior and my exact stops to let the brakes cool, and present this to the dealer.
I'm curious, how do you document brakes overheating ?

Re: Nissan "Out-of-Warranty" support for battery pack degradation

Posted: Mon Nov 27, 2017 5:59 pm
by abasile
SageBrush wrote:I'm curious, how do you document brakes overheating ?
There's probably a relatively easy way to measure the temperature of the rotors, though I wasn't shooting for that level of rigor.

It's common sense to most people near big mountains that you need engine braking (or regen in the case of a BEV) to safely descend long grades. Imagine if engine braking were disabled on a popular ICE vehicle like the Versa. It would not go over well.