Nissan's Included L1 (120v) EVSE

[TEG]

Bill, do you know if Nissan allows you to access 100% of the batteries actual upper limits? I talked to the Ford guy at the green fair here in Seattle and he said the Ford focus only allows access to 30% of it's actual battery capacity...

30% ??? That seems way too low. 80% I could believe. Or maybe he meant they keep 30% in reserve, and normally only use 70%?

 

[planet4ever]

I have a hard time believing we have access to anything near the top max on this battery but if someone has some actual data that shows what the actual capacity of the Leaf's battery is and that we are allowed to tap close to 100% of that, then that's a whole other story and please do tell.

For me for now, the inconvenience of loosing an extra few percents of battery life over time is nothing compared to the inconvenience of running close to empty regularly and having a lot of anxiety and possibly getting stranded. Getting stranded at all would be a serious buzz kill. I'm tending to not run the battery down below the 20 mile range, where the anxiety really kicks in for me, which makes it even more necessary to charge it all the way to have a decent range and relaxed experience with the vehicle. If it turns out that regularly charging the car to it's full capacity seriously reduces the batteries life, then I would be the first to argue the car should not be rated for a 100 mile range.

george

You're right, George, that there is no way Nissan would allow us to charge to 100% of total battery capacity. We would have batteries failing in months, rather than years, if we could. But you seem to be overreacting on the low end. 20 guesstimated miles is nothing to worry about at all. Watch the bars. So long as you have even one bar showing you are in good shape. The first low battery warning will come in the middle of that last bar. When the last bar disappears you are in a situation comparable to the needle on an old gas car approaching E. You still won't have seen the "very low battery warning", and even after that you have a number of miles (5 to 10) before the turtle appears. I got the "very low" a couple of miles from home one day and wasn't a bit worried.

Ray

 

[hill]

You can send in your L1 to me for the revision 1 upgrade for $239, and then have an electrician install a L6-20 with a 20a circuit. That should cost under $200 if your breaker panel is close by.

Then you can charge "in the middle" at 12a which still gives you reasonable overnight charges, without being as slow as 120v, or as hard as the full 16a rate. I am also coming out with a revision 2 upgrade which will allow full level 2 with possibly user selectable rates. You can also still charge at 120v anytime you like. . . . . . . . . . . . . . . . . . snip

ok this opens the door on rough back of the napkins numbers rattling around in MY head. Say I have a nice 'quick 220' appliance ... TWO 20a (120v) sockets that come off different legs of my main panel ... and all of that that now feeds into my pEEf mod'ed opportunity charger. I'm thinking this scenario would/could be more efficient than my existing arrangement.

Bill, do you know if Nissan allows you to access 100% of the batteries actual upper limits? I talked to the Ford guy at the green fair here in Seattle and he said the Ford focus only allows access to 30% of it's actual battery capacity, making abuse impossible. I seriously doubt Nissan would be that different. . . . . . . . . . . snip

Perhaps if you read up on Nissan's lithium Altra (put on the road in the 1990's)
http://en.wikipedia.org/wiki/Nissan_R'nessa
you might feel differently. They were some of the 1st EV's pulled out of the running, even prior to CARB reversing their EV mandate.

 

[Spies]

Perhaps if you read up on Nissan's lithium Altra (put on the road in the 1990's)
http://en.wikipedia.org/wiki/Nissan_R'nessa you might feel differently. They were some of the 1st EV's pulled out of the running, even prior to CARB reversing their EV mandate.

Would you mind expanding on your thought here? I am not sure of the point you are trying to make.

 

[ebill3]

Bill, do you know if Nissan allows you to access 100% of the batteries actual upper limits? I talked to the Ford guy at the green fair here in Seattle and he said the Ford focus only allows access to 30% of it's actual battery capacity, making abuse impossible. I seriously doubt Nissan would be that different. I guess I buy the reasoning that it's hard to imagine Nissan allowing 100% of capacity to be accessed and then having to fork out $$$ to replace all those batteries under warranty. They don't say charging to 100% voids the warranty, which if the degradation was as serious as it would be for true 100% charging, that would be devastating to the company financially or result in a lot of very angry customers and bad press. I was assured that a substantial drop in battery capacity would be covered under warranty... time will tell.

I have a hard time believing we have access to anything near the top max on this battery but if someone has some actual data that shows what the actual capacity of the Leaf's battery is and that we are allowed to tap close to 100% of that, then that's a whole other story and please do tell.

No, I do not know what percentage of the battery capacity is actually available in the Leaf.

I have no doubt that you heard the Ford representative saying that the Focus will use only 30% of capacity, but I find it hard to swallow. Either he did not really know, or there was a miscommunication, but 30% would be terribly inefficient. I have no credentials, but I do read a lot of what those with credentials write, and it appears that an 80% usage is commonly recommended. Allowing discharge to much below 3 volts per cell is detrimental.

I do believe Nissan allows charge to 100%, 4.2 volts per cell, when the say 100%. One hundred percent charge is not a Li Ion battery killer, but reduces battery life compared to a reduced charge level. I believe Nissan adequately covers that issue in their literature.

Bill

 

[GaslessInSeattle]

Bill, do you know if Nissan allows you to access 100% of the batteries actual upper limits? I talked to the Ford guy at the green fair here in Seattle and he said the Ford focus only allows access to 30% of it's actual battery capacity, making abuse impossible. I seriously doubt Nissan would be that different. . . . . . . . . . . snip

Perhaps if you read up on Nissan's lithium Altra (put on the road in the 1990's)
http://en.wikipedia.org/wiki/Nissan_R'nessa
you might feel differently. They were some of the 1st EV's pulled out of the running, even prior to CARB reversing their EV mandate.

Thanks for the link Hill, it's an interesting read. Wonder if anyone knows how they faired? Nice to know that issue was understood even then and likely well understood and accounted for in this generation: "It was managed by a passive system, ensuring the batteries never reach charge levels outside their recommended zones." I still wish the difference between 80 and 100% of allowed charging could be quantified in terms of how much added degredation we are adding to the normal decline curve over 8-10 years. Reducing stress and maximizing useability is important to me and will be to the mass market.
g

 

[GaslessInSeattle]

You're right, George, that there is no way Nissan would allow us to charge to 100% of total battery capacity. We would have batteries failing in months, rather than years, if we could. But you seem to be overreacting on the low end. 20 guesstimated miles is nothing to worry about at all. Watch the bars. So long as you have even one bar showing you are in good shape. The first low battery warning will come in the middle of that last bar. When the last bar disappears you are in a situation comparable to the needle on an old gas car approaching E. You still won't have seen the "very low battery warning", and even after that you have a number of miles (5 to 10) before the turtle appears. I got the "very low" a couple of miles from home one day and wasn't a bit worried.

Ray

Ray, it will take some time to really know how much to trust the guestimator, but I've seen it fluctuate quite a bit so I'm naturally reluctant to get down to depending on that last 20 miles and finding its really only 14.5 or something like that. When navigation can take into account changes in elevation, wind, rain, night vs day and temperature then maybe it will be more dependable. My ability to estimate the trajectory of all these factors is really not so good. My driving habits really don't change much, but that guestimator does and I understand there are limits to the technology and am not really complaining but take last night for instance. I didn't do as much opportunity charging as I might have during the day and had a spontaneous desire to visit a friend at about 10pm. I had 40 miles showing on the guestimator, but that was all from day time driving, no lights. It was raining, I needed ventilation to prevent the windshield from fogging. I went 21 miles and had 8 miles left on the guestimator when I got home, which got my nerves up a bit. So, I decided to push it, go a couple of extra exits and run the battery all the way down to again familiarize myself with where the actual hard line is. I drove an extra 8 miles or so and headed back up the hill for home and had the car zero out and start flashing those straight lines in the questimator field, which is what I intended to induce.

I don't think I'm over reacting though, I personally do not want to run it that close normally. I did turtle the car once, on purpose, and almost didn't make it up the hill to get it back in the garage (the power goes way down in that last phase, making climbing a steep hill questionable). I'm a technical scuba diver, and I'm accustom to the idea of planning with an extra 20, even 30% cushion around something this critical. Obviously running out of battery is not life threatening like running out of air to breathe, but the fear is substantial none the less. I find that when I leave at least 20 miles left on the gauge that I don't stress, then again, I am more likely to fill my gas tank when it gets below 1/4 tank than some people... like my father, who, for some reason, used to push it to the max, thinking somehow he was saving money and occasionally didn't make it to the next gas station... causing a delay of hours and a lot of hassle, I guess that's what's in the back of my mind and would like to avoid at all costs.
g

 

[eeman]

I have read through all of the posts on this topic and I did not see any that address the statement in the Owners Manual on p. CH-7 that says "Trickle charging is not recommended for regular use". The claim is that trickle charge is meant to be used to perform an emergency charge. This seems to go against owners using trickle charge as their primary charging strategy. I have been using this strategy myself until I get a 240V charger installed. I have however modified my use of trickle charge to limit the charging to 80%. I don't believe that you can specify 80% charge when using trickle charge so I have been guessing about when 80% is reached. Any comments?

 

[DarkStar]

I have read through all of the posts on this topic and I did not see any that address the statement in the Owners Manual on p. CH-7 that says "Trickle charging is not recommended for regular use". The claim is that trickle charge is meant to be used to perform an emergency charge. This seems to go against owners using trickle charge as their primary charging strategy. I have been using this strategy myself until I get a 240V charger installed. I have however modified my use of trickle charge to limit the charging to 80%. I don't believe that you can specify 80% charge when using trickle charge so I have been guessing about when 80% is reached. Any comments?

It's not recommended because it affects the "customer experience," not because it may cause damage.

If you set up a charging timer that is set for 80%, then the LEAF will only charge to 80%, regardless of Level 1 or Level 2 charging.

If you're happy with Level 1 charging, then there is nothing wrong with using it every day.

 

[Herm]

The Nissan Altra

http://avt.inl.gov/pdf/fsev/sce_rpt/altra_report.pdf

120 miles on the LA-4 cycle

32.7KWh pack, 804lbs not including the battery case hardware. Took 31 to 33KWh to recharge.

The SOC meter has 16 bars and is very linear.

Very nice car!

 

[eeman]

Thanks Darkstar, I will try that right now.

 

[ebill3]

You're right, George, that there is no way Nissan would allow us to charge to 100% of total battery capacity. We would have batteries failing in months, rather than years, if we could.

I beg to differ, as available data indicates that 100% charge is achieved.

The battery is made up of 192 Li-Ion cells, packaged in 48 modules. Each module contains four cells connected in series-parallel. That is, two cells in parallel, and then the two sets of parallel cells connected in series. The industry standard for full charge of a Li-Ion cell is 4.2 volts, so the resulting module voltage is 8.4 volts if fully charged.

48 X 8.4 volts = 403.2 volts.
The Nissan Leaf First Responders Guide, section 2-1.1, lists the battery as 403.2 volts.

Charging to 4.1 volts per cell is charging to about 80% of capacity. Charging to 80% should result in about 1.6 more charge/discharge cycles before the battery degrades to 80% of its original capacity, then if charged to 100%.

Bill

First Responders Guide: http://www.nissanusa.com/content/da...eaf/2011/2011-leaf-first-responders-guide.pdf

Li-Ion Battery Life: http://powerelectronics.com/portabl...y_charger_ics/804PET22li-ion-battery-life.pdf

 

[GaslessInSeattle]

Bill, you have a persuasive argument. I have not heard the first responder guide referenced before and that is a place where anything less than full disclosure could be deadly and full of civil liability. The fact that the 403.2 volts number meets up exactly with your calculation is rather sobering, but my knowledge of electricity is very limited.

Assuming what you are saying is true and assuming I'm getting it right, those of us who routinely charge to 100% could expect to see the battery degrade 1.6 times faster than if we went to 80% charging. I would think Nissan must be basing their 100,000 mile warranty on the assumption that using up the battery at the 1.6 rate would land the battery at a little above 80% capacity over 8 years/100K miles. Since industry standard is to consider the battery dead once it's below 80%, it would seem wise for Nissan to use that standard as their benchmark for warranty or risk seriously upsetting the popularity of EV's. Another way of putting it is, perhaps Nissan is saying that if you want to significantly increase the longevity of the battery beyond the warranty period, then charge to 80% mostly. If what they are saying is that if we charge to 100% on a regular basis and the battery reaches 80% capacity or worse prematurely, that it's on us, then we have a problem.

The other curve I'm trying to understand is where this 1.6 factors into the expected degradation of the battery due to time, not just in terms of number of cycles. Is time or cycles going to be the limiting factor here. Also, depending on how sophisticated the charger of the Leaf is, charging a large bank of batteries, allowing for different rates of charge to different sectors and so on, may result in a different decay curve than what we are reading about in the article linked.

Another curve I'm trying to get a handle on is how quickly these batteries will become outmoded technologically, as economy of scale and battery technology bring the price point down for a dramatically extended battery pack, likely within a few years rather than the better part of a decade (the warranty period), it may not matter if we all work the piss out of these batteries because chances are that we are going to be upgrading them sooner than they wear out anyway, when the 200 or 300 mile battery is available and at a price that makes it tempting enough.

If charging to 100% kills the battery within say 4 or 5 years then charging to 80% will probably be compelling to me. The problem is, if we really are allowed to access 100% of the batteries discharge/charge capacity, and seeing that the actual expected range with highway driving is more like 73 miles, and you add in a reasonable reserve like say 10 miles, you really only have a 60 mile range. This may still not turn out to be a big deal if true since that is more than the average person drives in a day, accept that it cuts down on spontaneity, particularly for those of us relying on the L1 charger. I think L2 is going to be my friend once I get it installed. I'll be curious to see of I can be part of the 80% club and still meet the flexibility needed for our spontaneous lifestyle once charging with L2 primarily. Good news is that it looks like we've gotten the green light for the free installation!

G

You're right, George, that there is no way Nissan would allow us to charge to 100% of total battery capacity. We would have batteries failing in months, rather than years, if we could.

I beg to differ, as available data indicates that 100% charge is achieved.

The battery is made up of 192 Li-Ion cells, packaged in 48 modules. Each module contains four cells connected in series-parallel. That is, two cells in parallel, and then the two sets of parallel cells connected in series. The industry standard for full charge of a Li-Ion cell is 4.2 volts, so the resulting module voltage is 8.4 volts if fully charged.

48 X 8.4 volts = 403.2 volts.
The Nissan Leaf First Responders Guide, section 2-1.1, lists the battery as 403.2 volts.

Charging to 4.1 volts per cell is charging to about 80% of capacity. Charging to 80% should result in about 1.6 more charge/discharge cycles before the battery degrades to 80% of its original capacity, then if charged to 100%.

Bill

First Responders Guide: http://www.nissanusa.com/content/da...eaf/2011/2011-leaf-first-responders-guide.pdf

Li-Ion Battery Life: http://powerelectronics.com/portabl...y_charger_ics/804PET22li-ion-battery-life.pdf

 

[Herm]

That emergency rescue document is strong evidence that they do charge to 100%.. but they wont discharge to 0. You can prolong the life of the battery by charging to 80% only.

 

[ebill3]

Bill, you have a persuasive argument. I have not heard the first responder guide referenced before and that is a place where anything less than full disclosure could be deadly and full of civil liability. The fact that the 403.2 volts number meets up exactly with your calculation is rather sobering, but my knowledge of electricity is very limited.

Assuming what you are saying is true and assuming I'm getting it right, those of us who routinely charge to 100% could expect to see the battery degrade 1.6 times faster than if we went to 80% charging. I would think Nissan must be basing their 100,000 mile warranty on the assumption that using up the battery at the 1.6 rate would land the battery at a little above 80% capacity over 8 years/100K miles. Since industry standard is to consider the battery dead once it's below 80%, it would seem wise for Nissan to use that standard as their benchmark for warranty or risk seriously upsetting the popularity of EV's. Another way of putting it is, perhaps Nissan is saying that if you want to significantly increase the longevity of the battery beyond the warranty period, then charge to 80% mostly. If what they are saying is that if we charge to 100% on a regular basis and the battery reaches 80% capacity or worse prematurely, that it's on us, then we have a problem.

The following is a lift from the LEAF site FAQ. It looks like Nissan is saying they base their life projection on 70%, which extends cycle life considerably, especially at 80% charge. Also, note that the data referenced in my last post is based on full discharge (?) to full charge cycles, and multiple shallow discharges add up to a full discharge.

Q: How many charging cycles can the energy storage device survive?

A: Like all lithium ion batteries, the Nissan LEAF battery will experience gradual capacity loss over time. We expect the battery to last over 10 years, however, there may be a gradual loss of capacity of 30% or more depending on your driving patterns, and the effect on your battery. The battery can be used afterward for storage applications. (My note: Wonder what that means, “used for storage applications”)

The other curve I'm trying to understand is where this 1.6 factors into the expected degradation of the battery due to time, not just in terms of number of cycles. Is time or cycles going to be the limiting factor here. Also, depending on how sophisticated the charger of the Leaf is, charging a large bank of batteries, allowing for different rates of charge to different sectors and so on, may result in a different decay curve than what we are reading about in the article linked.

As best as I can determine, time alone is not big factor in determining cell life. But, Li-Ion should not be stored at full charge for extended periods, and storage at high temperatures is also detrimental. For example, laptop computers are often used as a primary computer and left connected to the AC for extended periods – even 24/7. Under those conditions, it is recommended that the Li-Ion battery be removed.

I know no details of the charger, but I would bet money it has provisions for insuring the cells remain in balance. It would be technically quite easy to monitor each module’s voltage and adjust the charge to that module. Another laptop analogy. Unbalance is a reason why they seem to fail rather early. Cell voltage is monitored but not adjusted, so if a cell approaches a dangerous voltage, the entire charge is shut down, resulting in some cells not receiving a full charge. The danger of fire is almost eliminated, but the unbalance gets progressively worse, and soon the battery duration drops to zilch. That should not be the case with a well designed charging system.

Another curve I'm trying to get a handle on is how quickly these batteries will become outmoded technologically, as economy of scale and battery technology bring the price point down for a dramatically extended battery pack, likely within a few years rather than the better part of a decade (the warranty period), it may not matter if we all work the piss out of these batteries because chances are that we are going to be upgrading them sooner than they wear out anyway, when the 200 or 300 mile battery is available and at a price that makes it tempting enough.

Those bettery batteries are out there - just not ready for high current use or competatively priced.

If charging to 100% kills the battery within say 4 or 5 years then charging to 80% will probably be compelling to me. The problem is, if we really are allowed to access 100% of the batteries discharge/charge capacity, and seeing that the actual expected range with highway driving is more like 73 miles, and you add in a reasonable reserve like say 10 miles, you really only have a 60 mile range. This may still not turn out to be a big deal if true since that is more than the average person drives in a day, accept that it cuts down on spontaneity, particularly for those of us relying on the L1 charger. I think L2 is going to be my friend once I get it installed. I'll be curious to see of I can be part of the 80% club and still meet the flexibility needed for our spontaneous lifestyle once charging with L2 primarily. Good news is that it looks like we've gotten the green light for the free installation!

Congrats on the free installation. I rent and do not care to go through the hassle of getting landlord permission (if even possible), permitting, and inspection, so L1 will be my charge of choice. I am retired and rarely take a car out of the garage more often than every other day. Groceries, Doctor, recreation, and food and drink are within the 80% range, I think.

Bill

 

[hill]

Perhaps if you read up on Nissan's lithium Altra (put on the road in the 1990's)
http://en.wikipedia.org/wiki/Nissan_R'nessa you might feel differently. They were some of the 1st EV's pulled out of the running, even prior to CARB reversing their EV mandate.

Would you mind expanding on your thought here? I am not sure of the point you are trying to make.

Ok. Simply put - ask any business lucky enough to have gotten their hands on one of the Altra EV's and you'll hear stories of woe. Those early lithium chemistries were 'horrible' according to the lessees, when it came to reliability. Was that (meaning capacity loss) due to heat during charging? Who knows. There were less the 200 that were ever put into (fleet) use, and all of them were pulled back by the manufacturer early from the closed end fleet lease holders. Nissan never published what the issue(s) was/were regarding the lithium chemistry that they used. But my thinking says that they MUST have learned SOMETHING from their early projects. They were the only company that had the nerve to even try using lithium back in the 1990's. Here's a few archive / pic's that are still available on line:
http://www.altfuels.org/events/testdriv/altra.html
sorry for veering off topic!
.

 

[elbowelbein]

I have read through all of the posts on this topic and I did not see any that address the statement in the Owners Manual on p. CH-7 that says "Trickle charging is not recommended for regular use". The claim is that trickle charge is meant to be used to perform an emergency charge. This seems to go against owners using trickle charge as their primary charging strategy. I have been using this strategy myself until I get a 240V charger installed. I have however modified my use of trickle charge to limit the charging to 80%. I don't believe that you can specify 80% charge when using trickle charge so I have been guessing about when 80% is reached. Any comments?

It's not recommended because it affects the "customer experience," not because it may cause damage.

If you set up a charging timer that is set for 80%, then the LEAF will only charge to 80%, regardless of Level 1 or Level 2 charging.

If you're happy with Level 1 charging, then there is nothing wrong with using it every day.

Are you saying it can be charged every day, regardless of the amount of charge used? For ideal battery life, shouldn't the battery drop to 20% before charging up to 80%?

 

[davewill]

Are you saying it can be charged every day, regardless of the amount of charge used? For ideal battery life, shouldn't the battery drop to 20% before charging up to 80%?

Absolutely not. The only thing that's recommended is that you let the charge state drop below 80% before recharging. If you're only charging to 80% anyway, then you can charge any time opportunity knocks.

 

[mgoleta]

The battery can be used afterward for storage applications.[/i] (My note: Wonder what that means, “used for storage applications”)

1.) Grid storage. A used battery is still a 16KWh battery. This is enough to use as a house battery storage to be recharged at off peak times and used at peak time if you didn't have solar or as solar storage if you do.
2.) Off grid storage for houses/cabins, signage, lighting, etc. using solar/wind/gas generation for recharge.

 

[Stanton]

This turned into to a decent "how to prolong batt pack capacity" thread. Too bad you can't tell that from the title!