2k1Toaster
Posts: 408
Joined: Mon Nov 18, 2013 5:45 pm
Delivery Date: 12 Nov 2013
Leaf Number: 420903

Re: Charging frequency

Sat May 20, 2017 2:23 pm

jjeff wrote:
Not to derail this thread, but what happens when a Prii's battery pack goes bad and can it still be driven? I ask because I have a '06/'07 regular Priii(standard original NiMN pack) and I've read about people replacing the battery pack. I was just wondering if it was mandatory or just needed so the car would preform as new.
I mean it seems like the car should be able to drive even without the battery pack but maybe it won't with a defective pack....just wondering what I have to look forward to


A failed pack, after throwing codes, is usually driveable for a short while in emergency situations. The pack will barely accept any charge nor give it out. Fan will run 100% and the car will be sluggish and jerky. Really it's just for emergencies but if you're not worried about extra damage then you could maybe go a while.

Eventually the cell imbalance will be too great, or a HV isolation leak will happen, or the internal resistance will get too high. At that point the car will throw another set of codes and it will barely move and eventually stop.

The HV battery is used to start the engine and with other faults it will fail to go READY.
2013 Nissan Leaf SV with every option
2013 Prius C Package 4
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1981 DeLorean DMC12
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LeftieBiker
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Location: Upstate New York, US

Re: Charging frequency

Sat May 20, 2017 2:33 pm

One of the things I do is build EV's, repair HEVs, and even help test battery packs for big name auto producers.


Then I fail to understand why you don't have and use LeafSpy.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

2k1Toaster
Posts: 408
Joined: Mon Nov 18, 2013 5:45 pm
Delivery Date: 12 Nov 2013
Leaf Number: 420903

Re: Charging frequency

Sat May 20, 2017 2:53 pm

LeftieBiker wrote:
One of the things I do is build EV's, repair HEVs, and even help test battery packs for big name auto producers.


Then I fail to understand why you don't have and use LeafSpy.


Why do I need it? I know the batteries. I've had Nissan's pack in our lab before they were released to the public. I know what these cells are capable of and what the design is. A Leafspy does nothing other than give you a monitor into your specific pack health. Nissan won't replace it unless you fall into the specific warranty category. My Leaf pack with my hard usage will almost assuredly fall outside of warranty replacement as will pretty much everyone with a 2013+. So you're on your own to replace. I've looked at these packs with lab equipment counting coloumbs into and out of the pack, getting health and capacity curves. There is no information on a Leafspy that interests me.

As I've done with my Prius, I've replaced the pack with a custom solution using the OEM electronics. Not a rebuilt pack, but completely different cells with custom injection moulded plastics to fit in the old space. Cut the pack from 28 to 14 modules, but same pack voltage. Just used larger capacity cylindrical cells versus the smaller prismatic so each of my new modules is just over twice the size of two of the Panasonic/Toyota modules, but same size after mounting hardware and alignment bumps. Same Hybrid ECU, same temp sensors. New custom wiring internal to the pack. I've decoded all the CAN messages in the Prius and have previously built custom hardware that spoofs the various ECUs to run in "out of gas mode" aka "high speed forced EV" to even a really scary remote control drive. You can take over the acceleration and braking via the CANbus ad well as the steering wheel input. Then I could use my laptop and mouse to "drive" the car. I even put the laptop on the dash and drove it up and down the driveway using my cell phone as a remote client to the laptop to see the webcam and control the car wirelessly via a cell connection. Basically, it was a James bond car for a short period.

When the Leaf dies, I'll put in a new pack. The question I have is why bothering monitoring the battery yourself? It is going to fail, you can't prevent that. The most you can do is push it out a few years. And to me that robs the car of all the fun it's capable of. Quick starts, silent driving, and convenience of always having a charge and ready to go. Never having to worry about range, or fuel level, nothing. Just get in and go. I could probably eek out a few extra years if I played nice. But at that point why bother? I can today buy a brand new hail damaged Leaf from the dealership for peanuts.
2013 Nissan Leaf SV with every option
2013 Prius C Package 4
2012 Lexus RX450h
2006 Prius Gen II, pIV
2005 Honda Civic Hybrid
2001 Honda Civic EX
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1981 DeLorean DMC12
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LeftieBiker
Posts: 6934
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Charging frequency

Sat May 20, 2017 3:24 pm

Correct me if I'm wrong, but weren't you trying to use your car as an example for why others shouldn't worry about how they charge their Leafs? If so, shouldn't you be able to tell them how much capacity your car has lost after being treated as it has? You haven't even told us how many bars are showing. Your point seems to be that no matter what we do, the packs will degrade. You seem to imply that knowing the pack's condition won't help us to slow degradation. That's an interesting perspective, but it doesn't correlate all that well with our experiences with the packs.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

2k1Toaster
Posts: 408
Joined: Mon Nov 18, 2013 5:45 pm
Delivery Date: 12 Nov 2013
Leaf Number: 420903

Re: Charging frequency

Sat May 20, 2017 4:06 pm

LeftieBiker wrote:Correct me if I'm wrong, but weren't you trying to use your car as an example for why others shouldn't worry about how they charge their Leafs? If so, shouldn't you be able to tell them how much capacity your car has lost after being treated as it has? You haven't even told us how many bars are showing. Your point seems to be that no matter what we do, the packs will degrade. You seem to imply that knowing the pack's condition won't help us to slow degradation. That's an interesting perspective, but it doesn't correlate all that well with our experiences with the packs.


I have all bars at 26k miles on the odometer. Meaning I have more than 85% of the pack remaining. As mentioned originally I have no noticeable difference in range.

Do tell how knowing the packs condition would change the rate of the degradation... All that you can do is change very small parameters but the enemies of time and temperature will still get you unless you move or go back in time.

My anecdote is to show that with the absolute worst treatment possible by the user, me, the Leaf doesn't have any issues and is in better condition than other people who have sacrificed peace and have constant anxiety over range and battery degradation. That aligns perfectly with what everyone in the industry knows. Time and temperature kill batteries. Users have very little influence over the battery health with few exceptions. All this talk about keeping the battery at 80% charge and babying it just scares the crap out of normal people for no reason. If you want to get the least battery degradation, you'll have to pack up and move to a climate that condones it. If you live on a tropical island, it makes almost no difference what you do, your Leaf is going to die young. If you live at the Arctic research station your Leaf will be driveable until time gets it. And time is not easy to circumvent...
2013 Nissan Leaf SV with every option
2013 Prius C Package 4
2012 Lexus RX450h
2006 Prius Gen II, pIV
2005 Honda Civic Hybrid
2001 Honda Civic EX
1997 Honda Prelude SH
1981 DeLorean DMC12
and more...

LeftieBiker
Posts: 6934
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Charging frequency

Sat May 20, 2017 4:45 pm

Do tell how knowing the packs condition would change the rate of the degradation... All that you can do is change very small parameters but the enemies of time and temperature will still get you unless you move or go back in time.


First generation (2011-3/2013) Leaf packs would indeed degrade inexorably unless they were kept cool. Many of the anecdotes involving people who babied the car but still lost bars were with these packs. Starting with the chemistry change in April 2013, though, it became possible to extend pack life by controlling pack temperature if possible, because time-related degradation became a much more minor issue. I'll grant you that, if you act to limit pack heating with your own car, you don't necessarily need to know the exact capacity. When buying a used leaf, though, or when trying to see how changes in things like charging patterns affect degradation, you need to be able to read the pack with LeafSpy. It appears that your charging behavior is probably being balanced out by your pack not getting really hot. We tell people not to worry too much about charging patterns in Winter for that reason. It's in marginal or hot conditions that being able to track degradation becomes important - assuming, of course, that you can do something about limiting heat. And one way to limit heat is to limit charging (QC especially) when the pack is hot.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

2k1Toaster
Posts: 408
Joined: Mon Nov 18, 2013 5:45 pm
Delivery Date: 12 Nov 2013
Leaf Number: 420903

Re: Charging frequency

Sat May 20, 2017 5:07 pm

LeftieBiker wrote:
Do tell how knowing the packs condition would change the rate of the degradation... All that you can do is change very small parameters but the enemies of time and temperature will still get you unless you move or go back in time.


First generation (2011-3/2013) Leaf packs would indeed degrade inexorably unless they were kept cool. Many of the anecdotes involving people who babied the car but still lost bars were with these packs. Starting with the chemistry change in April 2013, though, it became possible to extend pack life by controlling pack temperature if possible, because time-related degradation became a much more minor issue. I'll grant you that, if you act to limit pack heating with your own car, you don't necessarily need to know the exact capacity. When buying a used leaf, though, or when trying to see how changes in things like charging patterns affect degradation, you need to be able to read the pack with LeafSpy. It appears that your charging behavior is probably being balanced out by your pack not getting really hot. We tell people not to worry too much about charging patterns in Winter for that reason. It's in marginal or hot conditions that being able to track degradation becomes important - assuming, of course, that you can do something about limiting heat. And one way to limit heat is to limit charging (QC especially) when the pack is hot.


I can tell you, there is still time degradation. Nissan didn't invent a magic battery. It is definitely prolonged, but again that is nothing the user has any control over.

And you can monitor the temperature with the bars on the Leaf's dashboard. It doesn't matter that the pack is 70.2C. If it is hot it is hot, knowing the exact hotness of the pack does nothing other than allow you to make a data point. Something I have billions or trillions of for various packs and chemistries in much more demanding situations. Unless you are QC-ing multiple times daily in the summer, none of this matters. You can track your battery's death down to the exact coulombs if you wish, but it doesn't mean your tracking has any effect on its death. Perhaps if you build a climate controlled box that you always parked your Leaf in, then maybe you can change the outcome. But this is one of those things you as a user have near zero control over. And lots of times things that users do meaning well, end up effecting things poorly.

Like all the Prius drivers who slowly crept along city streets trying to run off the battery pack as much as possible. Got 99.9mpg on the display! That was really common when Prii were new and novel. Heck, it is still prevalent with new buyers. Then after the tank of gas and the mpg's overall come in much lower than expected, everyone is confused why a non-plug-in gas-powered only car became inefficient with all that 99.9mpg driving factored in not realizing energy has to come from somewhere and converting it is not a 100% efficient process. In a Prius, driving it with quick acceleration and with minimal braking is the most efficient (aka "pulse and glide") yet the majority of people don't know and just think slower is better or put it in Neutral every chance they get. All sorts of stupidity the user does.

Point being all these stories about babying EV's is completely off the mark. It is pretty much the safe thing as praying every morning for the sun to rise again. Just because it rises, doesn't mean you had anything to do with it. Just because your battery hasn't died an early death, doesn't mean you had anything to do with it.
2013 Nissan Leaf SV with every option
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LeftieBiker
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Re: Charging frequency

Sat May 20, 2017 5:29 pm

And just because your pack hasn't died from the way you treat it doesn't mean that someone else in a different location wouldn't benefit from being more careful about charging.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

DaveinOlyWA
Gold Member
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Contact: Website

Re: Charging frequency

Sun May 21, 2017 8:50 am

hyperionmark wrote:
DaveinOlyWA wrote:
hyperionmark wrote:If short frequent charges were a problem then regen during braking would be destroying the battery.



It is along with jackrabbit starts... moreso than any other single factor

I believe you, but what is the reasoning? Seems like every other degradation variable is based around time and heat. This seems independent of those things. Just trying to learn more.


your statement implies that jackrabbit starts create no heat. Or is it no "significant" heat. So the question becomes "What is significant?"

I have to say that is a question I cannot answer since nearly everything we see here is highly filtered based on what the poster deemed important. There seems to be dozens of ideologies on that .


I have been a long time fan of neutral driving. Started waaaay before the LEAF arrived. It is a "very" small fan club, especially here. But it is essentially "no strings attached" miles. Since the traction pack is all but removed during neutral, its a win win. In my situation, sometimes regen is not the best option. (In reality, it should be avoided as much as possible along with brake usage)

But many here feel likes its some sort of safety issue. I have yet to hear a good or even logical explanation why. So its all about familiarity and comfort. Should you use neutral? That is up to you.

But lets look at another perspective; Regen is putting power into the battery at greatly varying rates and barring super high heat, its max is nearly QC speeds but at a higher SOC (only true in 24 kwh packs. This restriction is removed for 30 Kwh packs)

So we have regen at an elevated power level that is NOT available during a regular, monitored, controlled QC beyond a similar SOC, right?

Well, jackrabbit starts are "exactly" the same but mirrored. Same components, just running backwards so to speak. Charge out instead of charge in, every step essentially the same but reversed. Again, MUCH higher currents and nearly unrestricted. Why is this? Driveability obviously. Who wants to drive a slug?

But nothing is free (except driving in neutral! 8-) ) so we have compromises. These compromises caused too much degradation too fast so the power was tweaked. IOW, slightly less power off the time. a few more milliseconds added to the power ramp up. Pretty minor stuff really. Some noticed, I didn't simply cause I knew it was a trade off and didn't need it all that much. Not lucky enough to be first at the light (probably based on my perception that red lights are only pink for the first 3 seconds... :roll: )

What was probably a better solution was putting in more modules to distribute the load. Now many here will say it doesn't make a difference but for no other reason than to justify their behavior because in reality, no one knows for sure and definitely cannot quantify the effect.

But the key thing is that its only my supposition. I have no proof and my logic, in most cases, only works for me.
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2k1Toaster
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Re: Charging frequency

Sun May 21, 2017 2:10 pm

DaveinOlyWA wrote:
hyperionmark wrote:
DaveinOlyWA wrote:

It is along with jackrabbit starts... moreso than any other single factor

I believe you, but what is the reasoning? Seems like every other degradation variable is based around time and heat. This seems independent of those things. Just trying to learn more.


your statement implies that jackrabbit starts create no heat. Or is it no "significant" heat. So the question becomes "What is significant?"

I have to say that is a question I cannot answer since nearly everything we see here is highly filtered based on what the poster deemed important. There seems to be dozens of ideologies on that .


I have been a long time fan of neutral driving. Started waaaay before the LEAF arrived. It is a "very" small fan club, especially here. But it is essentially "no strings attached" miles. Since the traction pack is all but removed during neutral, its a win win. In my situation, sometimes regen is not the best option. (In reality, it should be avoided as much as possible along with brake usage)

But many here feel likes its some sort of safety issue. I have yet to hear a good or even logical explanation why. So its all about familiarity and comfort. Should you use neutral? That is up to you.

But lets look at another perspective; Regen is putting power into the battery at greatly varying rates and barring super high heat, its max is nearly QC speeds but at a higher SOC (only true in 24 kwh packs. This restriction is removed for 30 Kwh packs)

So we have regen at an elevated power level that is NOT available during a regular, monitored, controlled QC beyond a similar SOC, right?

Well, jackrabbit starts are "exactly" the same but mirrored. Same components, just running backwards so to speak. Charge out instead of charge in, every step essentially the same but reversed. Again, MUCH higher currents and nearly unrestricted. Why is this? Driveability obviously. Who wants to drive a slug?

But nothing is free (except driving in neutral! 8-) ) so we have compromises. These compromises caused too much degradation too fast so the power was tweaked. IOW, slightly less power off the time. a few more milliseconds added to the power ramp up. Pretty minor stuff really. Some noticed, I didn't simply cause I knew it was a trade off and didn't need it all that much. Not lucky enough to be first at the light (probably based on my perception that red lights are only pink for the first 3 seconds... :roll: )

What was probably a better solution was putting in more modules to distribute the load. Now many here will say it doesn't make a difference but for no other reason than to justify their behavior because in reality, no one knows for sure and definitely cannot quantify the effect.

But the key thing is that its only my supposition. I have no proof and my logic, in most cases, only works for me.


To add some science to this, you should reconsider what charge-time and discharge-time do to lithium based cells. Look up couloumbic efficiency as it relates to lithium batteries. A battery that is slowly charged and discharged spends more time oxidizing the electrolyte than one that is charged and discharged quickly. Assuming the same temperature charging/discharging slowly is actually worse than than charging/discharging quickly because it spends less time in the charge/discharge zones.

Jackrabbit starts (high C discharge, short time period) coupled with gliding where you have minimal charge in/out could be construed as having the best battery health. It is very low in efficiency with EVs but should be good.

Just injecting some science.
2013 Nissan Leaf SV with every option
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2005 Honda Civic Hybrid
2001 Honda Civic EX
1997 Honda Prelude SH
1981 DeLorean DMC12
and more...

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