Confirmation needed: Level 3 quick charge only on the SL?

Interesting.

BTW, I wouldn't dismiss what Nissan says. As you may know they have the longest Li battery experience in cars of any auto majors, AFAIK. They made Altra powered by Li in '98 even as GM EV1 was running on lead acid. IIRC, they also own their battery technology.

[ame="http://en.wikipedia.org/wiki/Nissan_Altra"]Nissan R'nessa - Wikipedia, the free encyclopedia[/ame]

Nissan Altra Electric Car from EV Rental

 

I don't discount Nissan's prior Lithium knowledge, but even so there are quite a bit of differences. The lithium chemistries of 10 years ago are vastly inferior to stuff made in this decade. Yes, they made a couple hundred Altra's way back when ... but that's no where near what (for example, Tesla) some car manufacturer's experience is now ... modernly ... with 5X to 10X as many vehicles to pull statistical data from. Who knows (also for example) how many hundreds of Mules Toyota had around, prior to the fleets of Gen III Lithium PHEV's that have been put on the roads.

I'll say this - what really blew me away was what darelldd said:

I was kinda getting sick of this thread, but MAN ... that really make a case for obtaining level III. asap.

 

Apparently Nissan has been developing Leaf for 5 years. And as I said, they own their battery chemistry - they don't need to get it from Panasonic etc.

After EV1 GM sold the battery tech to an oil company - while Nissan took the tech from Sony and kept developing it. What a difference in approach.

Ofcource, if lvl 3 makes the range better, I'm all for that !

 

I don't dismiss it. I just put more weight on the comments from people who have product on the street at this point. This isn't just a battery issue. It is a charger issue as well. As long as there is proper communication between the car and the charger, there really is no reason that a quick charge would degrade the battery.

I'm quite aware. I've driven a couple of the Li Altras. And maybe this is mentioned in the Wikipedia article... and maybe not (just checked - it isn't): The Altima had the single worst battery track record of any of the EVs of the 90's. Serious range degredation before the first year was up. Few of them made it through more than few years before the range was useless. I don't say this to dump on Nissan at all. I love what they're doing with the LEAF. I love that they're making their own batteries. I seriously want them to succeed. I've just experienced some stuff that not everybody is aware of.

Ah, here we go. Here's a shot with two Altras parked next to my Rav many years ago. My Rav is still being driving daily... the Altras stopped working long ago (oh, and they weren't quick charged!)

 

Charging to 80% means 80 miles nominal range instead of 100. If you routinely allow a 10% safety buffer for unforeseen traffic conditions or detours, and 10% for less-than-ideal driving style and higher speeds than the test cycle that gave the 100 mile figure, 80% charge means a usable range of roughly 64 miles instead of 80 miles for a full charge.

The trade-off is reduced range for extended life. It seems to me that Tesla provides the option for an 80% charge because that gives longer life. So you charge according to your driving plans. But the fast-charge stations they are talking about, that give you 80% charge, also mean 80% range, unless you have time to wait for the slow charge to top off your pack.

If I had a real-life highway 350-mile range I could sell the Prius and just drive an EV. That would get me to my two primary hiking locations in Canada, where I'd have between one and two weeks to let the car sit and re-charge from 110-v 15-a. I'd do a 100% charge for those trips, and 80% for everything else. Longer trips would be two days anyway, so charge overnight, assuming that's available.

 

From what I've read heat is the main reason for degradation due to fast charging.

 

Fast charging always develops more heat due to high current against high internal resistance when battery is depleted. Heat is bad for Li ion battery.
The reason for fast charging only to 80% is because when the battery is at 80% charge, the charger has to change from constant current charging to constant voltage charging. The last 20% charging will take a lot of time, say the first 80% takes 30 min and the last 20% another 30 minutes or longer, so it defeats the fast charging purpose.
For those who have experience of Li ion battery charging methodology will understand what I am saying.

 

• Heat is the biggest enemy here.
• rapid charging creates more heat.
• rapid charging doesn't create destructive heat until after 80%... though even "rapid" charging tapers off well before 80% is reached - again - to avoid over-heating.

The entire reason the quick charge stops at 80% is to avoid over-heating the batteries.

• Even when charged slowly, tons of heat is created when you get close to 100%.
• Doesn't matter how much communication is going on - the serious heat happens above 80%. Every time. Heat IS a factor - but only after 80%.

Whoa! What the heck have you heard? I've found nobody who says that heat is a big issue between 20 and 80%... or that heat is NOT an issue between 80 and 100%. My guess is that what you've heard is that quick charging will degrade batteries if the batteries are allowed to get hot. And that happens when charging is not tightly controlled. That isn't the case here.

The only reason it is better (and I thought I'd already said this??) is that the quick charge terminates at 80%. Charging slowly to full creates significantly more heat than charging rapidly to 80%. Just to be clear - if the pack were quick-charged to 100% the battery would be destroyed in short order.

Ha. You know me better than that! This has nothing to do with Mitsubishi's batteries or chargers. This effect is true for all modern battery chemistries including NiMH and Li. My only point of bringing Mitsubishi into this is that they're saying logical things, and proving it in the real world. But honestly - we've had fast charging for 15 years. None of this is a surprise - and all of it is well known and documented. Aerovironment has been on the leading edge of this since the beginning.

I hope this helps without being annoyingly redundant.

 

And the reason this happens is to curtail the charge rate to... wait for it... keep the heat down!

 

The Second Law of Thermodynamics

-- by Flaunders and Swan

 

So if L1 or L2 were to charge only to 80%, would it be the same degree of harm to the battery as an L3 charge to 80%?

 

Why is it then, the RAV4-ev'rs occasionally seem to NEED to charge to 100% ?? different chemistry? (nickel)

.

 

An article on Page 21 of the current (June 2010) issue of CurrentEVents (newsletter of the Electric Auto Association) says that at initial launch the Leaf will have L3 fast charging as well as 110-volt "emergency" charging.

It will have a 24.5-foot "emergency" cable with a J-1772 plug on one end and a standard 3-prong 110-volt plug on the other for charging from standard household current. They don't anticipate this being used under normal conditions because of the 22-hour zero-to-full charging time.

I'd point out, though, that if you only drive 50 miles, it would only take 11 hours, and those of us who will routinely drive less than 50 miles could do perfectly well with L1 charging.

 

Also confirmed by Nissan, not only will the SV NOT have an L3 option, L3 can not/will not be retrofittable (in case you find the $700 port in the salvage yard some time down the road, in the not too distant future). Sounds like a challenge to all the DIY'ers out there. I'll be considering my OWN DIY project ... more batteries. After all, if the Tesla can mod their pack capability, it stands to reason Leafers can too.

BTW the L2 & higher power/L3 network has been laid out in the Nashville area ... at least the 1st 425 miles worth. They get to be 1st:

http://www.nashvillepost.com/news/2...ng_tennessee_electric_car_infrastructure_plan


So it looks like L3 / DC outlets will be right on time for some of those that opted for the L3 port being integrated into their SL's.

.

 

Wait a sec - there are guys out there modding their Teslas? OT - but post more details.

 

oh sorry ... no, i only meant Tesla traction battery packs can be ordered in different sizes ... large to small.

 

You must mean on the Tesla S - thought you were talking about the Roadster. I'm sure different battery pack sizes are coming in future cars - but I wouldn't expect it for a few years.

 

The spec sheet doesn't seem to mention that the L3 (or DC charge, or quick charge, or whatever it'll be called) wiring/connector must specifically be ordered from the factory (or not).

BTW the first I've heard of this issue was today when our guide at the Drive Electric tour mentioned it, and he was of the camp that it'll only be available in the SL trim and still be an additional option on top of that. It's slightly disturbing that I haven't seen this anywhere on a printed spec sheet, but i suppose it's understandable if the spec is still being worked out.

Oh well. It'll be at least a year before I buy a Leaf, so this should be sorted out by then.

 

I (and many others) have already ordered their Leaf with the [ame="http://en.wikipedia.org/wiki/CHAdeMO"]TEPCO CHAdeMO[/ame] DC quick charge port. 20-30 min empty to 80% full chargers are a reality.

Yes, it is a $700 option only available on the SL trim - unless you are part of the ETEC/EV Project in which case you get it for "free".