Details on Nissan Leaf battery pack, charge rates, lifespan

http://green.autoblog.com/2010/05/27/details-on-nissan-leaf-battery-pack-including-how-recharging-sp/

"In Smyrna yesterday, Nissan's director of product planning, Mark Perry, gave AutoblogGreen some more information on the Leaf battery pack. As we know, Nissan says the 24 kWh pack gives the Leaf a 100-mile range on the gentle LA4 cycle (meaning it probably isn't a totally reliable guide to estimate real-world driving). Still, this means the test packs have been charged and discharged a lot, because Perry said Nissan has done "hundreds of thousands" of miles of reliability testing on the battery packs, including dunking them in a pool and freezing them. Not that we'd expect him to say anything different, but Perry is confident that the battery pack is totally safe."

http://green.autoblog.com/2010/05/27/details-on-nissan-leaf-battery-pack-including-how-recharging-sp/

How you recharge the pack will affect its life. Nissan has said it expects to Leaf drivers to have around 70 to 80 percent capacity left in the pack after ten years. What will get drivers to the upper or lower end of that range? The amount of fast charging one does. With regular Level 2 charging, drivers should expect 80 percent live left in the battery. With a lot of Level 3 charging – two or three times a day – the pack will only be at the 70 percent level. Level 3 charging is appealing because it can get the battery from zero to 80 percent full in under 30 minutes, but there is a very clear drawback if it becomes a habit. Perry said that most people will be happy with 240V home charging

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Well, that'll work for me. If I get the 65 miles a day combined city/highway I'm hoping for, the need for me to charge anyplace but home drops to just about zero.

Merging topics.

evnow said:

Merging topics.

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Dang, and I checked before I posted. :roll:

Does this mean that if I charge only with 110V, that I will still have about 90 percent capacity after 10 years?

trentr said:

Does this mean that if I charge only with 110V, that I will still have about 90 percent capacity after 10 years?

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nope, the lithium pack also has a "calendar shelf life" as well, regardless of use/no use, charge/no charge. That will be the limiting factor, not the charge rate.

I've always been really skeptical on how good the LA4 figures really are. However, I recently saw the LA4 figures for the new Ford Fiesta.

The Ford Fiesta has been available in Europe for some time, and I carried out a week long road test in one last year. It had the same engine and gearbox to the specification tested for LA4. I was within 0.6 mile of the official LA4 fuel consumption figures during my own economy testing and exceeded the official European figures.

To be fair, it's the only time I've managed to achieve that in any car, but it proves that it can be done.

Very interesting Mike. Good information, were you trying to directly duplicate the cycle or were you 'just' recording how it operated as you went about your tasks?

Well, somewhere earlier in another thread was the question as to whether we could dispense with the charger altogether if we can suffice with the trickle charge. At that time I thought Nissan was requiring the charger to be installed as a qualifier to reserve, but now it looks like that might only be for the EV Project. I typically drive < 5 mi. before noon and then the car sits all day and all night. I would think that I could charge off 110V house current just fine, but the question of how that affects battery life was not addressed in this info. It's still not clear to me whether this approach is permitted, practical, or financially wise. I have 220 in my garage now, so it probably wouldn't be all that expensive to put in the charger, and I have to believe that there would be times I need to charge faster than 18 hours.

Rat said:

I typically drive < 5 mi. before noon and then the car sits all day and all night. I would think that I could charge off 110V house current just fine, but the question of how that affects battery life was not addressed in this info. It's still not clear to me whether this approach is permitted, practical, or financially wise.

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I'm absolutely convinced that it is permitted, practical, and financially wise in cases like yours, with a couple of qualifiers:
- The 110V outlet needs to be at least 36" off the garage floor (most are).
- It needs to be on a 20A circuit or on a 15A circuit with little if any other load.

Rat said:

I have 220 in my garage now, so it probably wouldn't be all that expensive to put in the charger,

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Don't be so sure of that. What you probably have is a 30A dryer circuit. The EVSE needs 40A, which means fatter wiring between it and the breaker panel. That's not too bad if the wiring is in conduit, but in older homes it is likely to be stapled to the studs inside the wall. And, of course, it has to be a dedicated circuit, so this assumes you do not have, and never intend to have, an electric dryer in the garage. Then there is the slight chance that an extra 10 A would overload your service coming into the house. Things could really get expensive then.

Rat said:

and I have to believe that there would be times I need to charge faster than 18 hours.

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Only if you intend to drive 80 or more miles in each of two consecutive periods with only one shorter charge time between them.

If you are out of circuits in your breaker panel, or need to run a new line to your garage for your EV charger, this is a fairly inexpensive way to go, its a combination meter/8 circuit or (4) 2 pole, breaker panel, can be used for overhead or underground service, 200A breaker included, and it has "feed through lugs" so it can be used to re-feed your existing panel, then just run a new line from this to your garage, for the EV charger. As a side benefit, you can also use this to connect a solar PV grid tied inverter to as well..

http://www.lowes.com/pd_79498-296-RC816F200C_0_?newSearch=true&catalogId=10051&productId=1196613&Ntt=rc816f200c&N=0&langId=-1&y=9&x=40&storeId=10151&Ntk=i_products&ddkey=http:SearchCatalogDisplay

$140 from Lowes.. of course you still need an elctrician, and the permits, etc.

i plan to charge primarily with 110 volts and sure it takes longer and if driving a ways two consecutive days, it could be a struggle. but public (and FREE) 110 volt charging stations have been available in my area for years. i charge my Zenn now (granted, the most i ever need to charge it is only a few hours) so i am all set.

as EV's become more popular, opportunity charging with 220 will be come common place. shopping centers, workplaces, park and rides, etc. granted i am guessing i will be paying 3 X my home rates, but even at that, i am still saving a ton of money over any gas option.

The 120v "included" EVSE charger cord should work well whenever slow charging fits your usage pattern.

The Slow, Medium, and even Faster should not stress the battery very much.
The Quick will only rarely be used for more than a partial charge.
Some will "never" use it.

Slow: 120v * 12a = 1.4 kW (20 hour) => 5 miles for each hour of charging
Medium: 240v * 15a = 3.6 kW (8 hour) => 12 miles each charge-hour
Faster: 240v * 32a = 7.2 kW (4 hr) => 25 mech (pronounced "meech")
Quick: 440v * 100a = 44 kW (80% in 30 min) => 160 mech
(all approxomate, and "LA4 miles")

Is there some sort of "standard" for "miles for each hour of charging" ? "meech" ... "mech" ?

My preference is MPHC = "Miles Per Hour Charged". Close to "mph" ... but not too close. Where this becomes interesting is on long distance drives when comparing your "traveling speed" with your "resting speed" (while the car is charging and you're having lunch, etc.).

No, there is no standard verbage ... yet.
But, the "slang" words that get into the dictionary only have to appear "in print" about 5 times!
"Mech, mech, mech, mech, munch!"

However, I think "mech" (miles [for] each charge-hour) is easier to pronounce than "mphc" (miles per hour [of] charging).

And, the metric "kech" (key-ch) version?

probably wont be one since the rate of charge is dependent upon the SOC. (state of charge)... miles per killowatt we use frequently and i vote MPK would be good

Over a wide range of SOC, the charging rate is likely to be constant.
In hot conditions, the Quick charge rate might be reduced.

Only with some cells nearing "full" does the charge rate need to be drasticaly reduced.

That is probably why Nissan gives the 80% Quick-charge time, not including the extra time needed to charge to 90%.

Also, the times do not include the extra time needed to "balance" the cells occasionally, when needed.

If a few cells are "only" 3% high, and a few are 3% low, running the pack from 10% to 90% would run the "high" cells between 13% and 93%, and the "low" cells between 7% and 87%.

However, I believe that it is not yet "known" just how the LEAF will handle keeping the cells balanced.

DaveinOlyWA said:

probably wont be one since the rate of charge is dependent upon the SOC. (state of charge)... miles per killowatt we use frequently and i vote MPK would be good

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MPK is definitely of use ... and I think already a standard ... or it's inverse (Wh/mile). But here we want to give the "average Joe" (?Josephine) an estimate as to what (how many miles) to expect when they plug in ... and express it in terms of "wait time".

Other than the fact that "miles-per-hour" is normally a speed (of a moving object) ... the MPH (without the "C") is usually what comes up in conversations. Q: How long does it take to charge? A: either a time frame (4 hours/8 hours), because most people asking are assuming 0-100% (getting a full "tank" (of electrons)), *OR* a "speed" of charging, i.e. "10 miles-per-hour", "40 mph" ... etc etc ...

ok i totally missed the MECH thing.

i have to dispute the 110 volt figures though. i dont see that in the Zenn. granted, different charging system and i dont know what it puts into the battery pack (efficiency rating, etc) but mine starts charging at 16 amps and wanders down from there.

so i would have to put a bit more than 4 MECH for the 110 volt figure.

i so have to think that the Zenn's system is far below the efficiency level of the Leaf making the Leaf rates higher. now, seems to me i saw somewhere that is was 6-8 hours to full for 220 and 15-16 hours for 110 which implies about 12 MECH for 220 and 6 MECH for 110 which in my experience is probably about right