Possible Widespread 2018-19 Traction Battery Quick Charge Problems

SageBrush said:

Joe6pack said:

Even at 22 kW, the new LEAF should be able to charge from 20% to 80% in about an hour. I question whether the low charge rates later in the trip we're the fault of the LEAF or the chargers. No one else has seen charge rates that low under even extreme conditions.

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If the car starts out at 22 kW at 20% SoC, it is not going to be anywhere near that power level above 50%, let alone up to 80% SoC.

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Do the math.

38kWh actual battery size.
20% to 80% is 60% of the battery.

60% of the battery is 22.8kWh.

Oils4AsphaultOnly said:

Agreed with this, but if charging power is limited, then the amps decreasing when voltage goes up would make more sense.

22kw @ 20% SOC would be charging with ~349V (guessing based off my 30kwh battery) and 63A. Since the car dictates the amperage drawn during the charge cycle, then it'd make more sense to reduce the amps as the voltage increases. Holding the amperage stable as voltage rises would increase the charge power and thus accelerate the heat gain - that's counter productive to the initial action of throttling charging power.

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Well I'm not sure. Maybe that's true. But I think heat generation is more related to current than power.
In case of wire conductors for example, voltage has little to do with heat loss. But current is.
It's reasonable to suspect same story inside the pack. 60A at 350V generates as much heat as 60A at 390V.
Though battery is more complex. Internal resistance changes all the time. And battery struggles to charge when voltage
starts to hit the upper end. Not sure how that affects heat generation. Anyway, I'm just noting that it has not been confirmed
that heat generation is a function of power and not current.
In that I'm sure that there is a lot of heat generated when SOC drops below 15%.

On previous Leaf, thermal throttling was limited by amps.

Unfortunately, my car budget is more like $10K CA, which is what I spent on the 2013 SV that I bought in WA and imported. Best car decision I ever made, as gas prices in BC are ludicrous and getting nothing but worse. I'll probably buy a second LEAF sometime in the next year or two, if I can find another bargain.

arnis said:

Well I'm not sure. Maybe that's true. But I think heat generation is more related to current than power.
In case of wire conductors for example, voltage has little to do with heat loss. But current is.
It's reasonable to suspect same story inside the pack. 60A at 350V generates as much heat as 60A at 390V.
Though battery is more complex. Internal resistance changes all the time. And battery struggles to charge when voltage
starts to hit the upper end. Not sure how that affects heat generation. Anyway, I'm just noting that it has not been confirmed
that heat generation is a function of power and not current.
In that I'm sure that there is a lot of heat generated when SOC drops below 15%.

On previous Leaf, thermal throttling was limited by amps.

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I totally get the point about heat from resistive wires being based on current and not voltage.

I think the key to reconciling this with what we're seeing is that the batteries internal resistance becomes a bigger issue during the thermal throttling situations than convential wisdom allows (like how 2nd-order aerodynamic forces were overlooked in the Tacoma-narrows bridge debacle).

I pulled this from a forum post linked earlier in this thread: http://mynissanleaf.com/viewtopic.php?f=27&t=25519&start=10#p522443
-- https://speakev.com/threads/worried-about-leaf-2-rapid-charging-rate.101025/page-27#post-1932705

"Plugged into the charger on 12% and was given an estimate of 1.5 hours to reach 75%. Only taking 22kw from the start.
K[1].jpg

Nearly an hour later and I'm only at 65%."

That's 47% of 38kwh (~18kwh). With a start of 22kw, charge power (and thus current) had to have tapered sometime during the charging. Any increase of charge power would need a steeper decrease to compensate to arrive at a lower average. At the higher voltage levels, the current would have to drop significantly to achieve this. I guess we can extrapolate based on the fact that the charging session needed to deliver another 3.8kwh in the remaining 30mins? But it wouldn't change the overall conclusion that amps were reduced during the charge cycle.

Edit: re-read Arni's post, and I think I've beaten a dead horse. My apologies!

alozzy said:

gas prices in BC are ludicrous and getting nothing but worse.

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Los Angeles drivers are paying $3.42/gallon, Vancouver drivers are paying $5.63/ gallon (prices in California are above national average)
(Article on March 6, even worse now)

https://globalnews.ca/news/4067186/metro-vancouver-has-the-priciest-gas-in-north-america-and-the-numbers-keep-climbing/


My Leaf costs me 1.25 to 2.5 cents (summer /winter) per KM based at 130w/KM. (10 cents /kWh)
There are a lot of people still not convinced to this point, ( basically the limited range) but I feel that will change very soon (60kWh) .My only hope that the infrastructure will be able to keep up.

ElectricEddy said:

alozzy said:

gas prices in BC are ludicrous and getting nothing but worse.

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Los Angeles drivers are paying $3.42/gallon, Vancouver drivers are paying $5.63/ gallon (prices in California are above national average)
(Article on March 6, even worse now)

https://globalnews.ca/news/4067186/metro-vancouver-has-the-priciest-gas-in-north-america-and-the-numbers-keep-climbing/
.

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If that is $5.63 Canadian for 4 litres,
it works out to $4.45 USD per US gallon

A little less, I think. So far, prices have topped out at $1.50/l CA, which is around $4.25/gallon US. However, we are expected to be up to $1.60/l CA this summer.

We pay about 11¢ per kWh for electricity, which is almost entirely generated using hydro power.

We are also finally starting to see more DCQC stations coming online over the next few months, very much needed.

A very controversial hydro electric generation project (site C) is being built in BC, which environmentalist say is going to generate unneeded power while flooding pristine wilderness areas.

However, if the politicians in BC were smart, they would create policy that ensures a domestic market for that new electricity supply by getting a million ICE cars off the road and replaced by EVs. It's far more likely that instead the majority of that new electricity generation will be sold to the US. Money talks...

alozzy said:

A little less, I think. .

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One CAD = 0.78 USD
3.78 liters = 1 US Gallon

At 1.5 CAD per liter,
1.5*3.78*0.78 = $4.42 USD per US gallon

That article you referenced was trumpish garbage. Have Fox "journalists" infiltrated your newspapers ?

Fair enough, I didn't bother looking up the current exchange rate, used .75 as that's where our dollar is typically at.

I didn't reference any articles...

Guess the prognosticators were right. I just went out for a drive and passed a local gas station - price at the station was $1.57 per litre. I really need to get rid of my ICE...

Oils4AsphaultOnly said:

Joe6pack said:

Whatever floats your boat buddy. Want to go unchallenged, by all means put me on ignore. If it takes a wall of text to get your point across, you probably don't have a point.

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I couldn't find an ignore list, but there's an option to add you as a "foe". Was that what you meant?

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After a site update that must have occurred in the last couple months, I found the user who was previously on my list of users to be "ignore"d is now on my list of "foe"s. I guess the "ignore" functionality is the sole consequence of being on the "foe" list. I wonder what the functionality of the "friend" list is.

alozzy said:

I didn't reference any articles...

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Sorry, my mistake. It was ElectricEddy

LeftieBiker said:

How about "DCFOC" for "DC Fast ONCE Charging"?

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How about One Trip Pony

SageBrush said:

alozzy said:

A little less, I think. .

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One CAD = 0.78 USD
3.78 liters = 1 US Gallon

At 1.5 CAD per liter,
1.5*3.78*0.78 = $4.42 USD per US gallon

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Google fortunately also can do all the conversations based upon current conversion rates.

Google for 1.50 canadian dollars per litre in us dollars per us gallon. It also currently agrees with your answer:
4.42377606 U.S. dollars per US gallon

cwerdna said:

Google fortunately also can do all the conversations based upon current conversion rates.

Google for 1.50 canadian dollars per litre in us dollars per us gallon. It also currently agrees with your answer:
4.42377606 U.S. dollars per US gallon

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Yep -- Google is one smart conversion calculator ... although a bit of a show off. How many parts of a penny do we really want ?

I've tried to stump the calculator. IIRC it can compound THREE conversions, meaning f(g(h(x)))

^^^
Unfortunately, when I was taking a seminar long ago related to energy efficiency in buildings, it didn't have certain units like foot-candles. My memory's foggy now as to what conversions I needed.

Some other funny ones include:
10 mph in furlongs per fortnight
10,000 leagues in meters
50 miles per us gallon in teaspoons per mile (50 mpg in teaspoons per mile used to work, but I guess you need to be more specific now)

This is useful when comparing alien to American ways of expression fuel economy:
4.5 litres per 100 km in miles per us gallon

cwerdna said:

^^^
Unfortunately, when I was taking a seminar long ago related to energy efficiency in buildings, it didn't have certain units like foot-candles. My memory's foggy now as to what conversions I needed.

Some other funny ones include:
10 mph in furlongs per fortnight
10,000 leagues in meters
50 miles per us gallon in teaspoons per mile (50 mpg in teaspoons per mile used to work, but I guess you need to be more specific now)

This is useful when comparing alien to American ways of expression fuel economy:
4.5 litres per 100 km in miles per us gallon

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What do you mean - an African or European Swallow?

Estimating the Airspeed Velocity of an Unladen Swallow

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http://style.org/unladenswallow/

You have to know these sorts of things when you're King.

It's interesting to note that Nissan just announced their e-NV2000 van will come with a 40KWH battery pack. Oddly enough, it will have active TMS because Nissan figures that the truck is likely to be recharged several times a day and will need active cooling to achieve that. They're not putting it in the car though because it would add to costs. Apparently, you don't need to charge the Leaf more than once a day according to Nissan.

What kind of TMS?

I believe it is liquid-based Active Thermal management on this updated mini-Van.

The Leaf is targeted at a different market (90+% who will not need to Fast Charge at all) hence why the 2018 Leaf has no ATM. Keep entry price down to spur more adoption. That is my understanding of their mindset.