What proportion of that weight is in the casing of the cell though? I would imagine in larger cells the containment for the actual chemical compound would be a much lower percentage of overall weight.
Yeah, Panasonic has a Wh/L figure too.
I was reading about the Tesla. It is Motor Trend car of the year in 2013. EPA range estimates of 265 miles on a single charge. You can get as high as 300 miles on one charge. The car uses over 7000 Li-On 18650 batteries in the floor of the car which makes up the battery compartment. 8 year, unlimited mileage warenty on the battery. The car is a large sedan about the size of a Mercedi S class sedan. It seats 5 plus an option for 2 more rear facing seats in the back for kids up to 70 lbs.
Fun part is the car will go 0-60 in less than 4.5 seconds. You can charge it at home at a rate as high as 62 miles for every hour charging until full capacity is reached in about 5 hours from completly empty.
Tesla is building a network of super charge stations along interstates and plans to have 1500 stations up and running by the end of this year. The super stations recharge at a rate of 150 miles in one half hour and will be built next to rest stops and resturants so you can recharge while taking a break. Charging is free for as long as you own the car. You will be able to drive from coast to coast without paying a penny for fuel. Top end cost is just over $100k.
But for automotive use, power density is also important. 400Wh/kg is fine, but not if you can only get it out at 5mA. Power density is rather important for electric vehicles.
It sounds like they have that cracked, but hopefully not at the expense of cell life.
Hmm, Tesla. The only thing I remember about them is that they built a car that would drain its batteries to 0 volts if the car was stored too long. When a few people bricked their $20,000 batteries that way, tesla told them to get stuffed. That kind of customer service speaks volumes. (To be fair, tesla did put a note in the owner’s manual about the issue. Since I don’t own a tesla, I can only guess that it said something like, “… our marketing weasels want to pretend that this car has a lot of range, so our engineers weren’t allowed to put in a $5 circuit to protect your expensive batteries and when you complain, we’ll act as if it’s not our fault.”)
An oxymoron, no? A $25,000 battery will make cars more affordable? That’s what a Prius cost. How will it “slash” prices? The battery in a Prius cost around $2300.
Interesting tech for sure, but that’s a nonsensical statement.
The latest Tesla (top pic) may be aimed at the luxury mkt like the Maserati Granturismo/Quattroporte:
Thanks for that link. Glad to hear someone domestically is pushing for better EV battery tech. I drive the latest Prius Plug In Hybrid with the 4.4 kWh lithium pack. The way this vehicle manages energy and delivers MPH still amazes me after 20K miles driving it. I think this blend of combustion/electric is the future for consumer commuting. Pure electric has too many hurdles, even at $6-$8 gasoline.
Hopefully Envia Systems are not working in a vacuum. Overall pack weight vs range vs charge time is a tricky equation to master. Plus working temp of the pack itself and the working temp of the inverter during summer driving. Then there’s the 20% loss in pack capacity during winter driving.
My commute is 18 miles round trip w/o charging at the destination. My average MPG is 145.
Seems like a mild rebuke, a deceptive graph, but a brief look shows company apparently doing well now.
They aren’t gone. That is pretty good in this economy.
They are done, never was able to deliver the battery to GM.
Learned a lot about the underlying chemistry of Lithiums from this article.
But sad truth appears to be that there is no magic bullet in battery technology.
I like the assessment of Tesla as well;
“With his sleek, high-tech Model S, Musk has made electric vehicles a commercial and Wall Street sensation. But he has not revolutionized electrochemistry. Rather, Musk’s cars are powered by thousands of off-the-shelf Panasonic nickel-cobalt-aluminum cylindrical cells—big, heavy and volatile batteries that push the base price of the 200-mile version of the Model S to $71,000. They are a design-and-engineering solution to the problem of making electrics competitive with cheaper gasoline-propelled vehicles. While sexy, their price makes it far from certain that Musk’s approach will lead to large-scale consumer adoption.”
A friend has a Nissan Leaf and that thing can’t even go 50 miles on a charge unless it is pure relatively level turnpike travel.
He just uses it around town, so it suits him, but no way in heck can it be your only car with a family.
Thanks,
Keith
So how much did the American taxpayer get soaked for this—yet another—failed green venture??
Sounds like something is bad in his battery packs, that does happen.
Breakthrough in chemistry is nice, but what we are waiting to see are the full effects of competitive mass production reducing the cost.
What seems sort of promising to me are plans like SmartCar where you get a 10 year lease on the battery pack including replacements during the period.
A practical option I think is to go hybrid with a pack good on its own for say 20 to 30 miles, but have lots of quick and easy options for recharging like in parking lots so the fuel based engine rarely needs to be used.
Still alive and feeding happily on government money.
The Tesla uses 7000 18650’s. If each battery weighs 46 grams, then just the batteries in the pack would weigh 710lbs. I have seen The 85KWh number used to rate the capacity of the pack. That would be how much you could get on one of the first charge cycles before it was totally depleted. (not something you would really want to do). Each successive charge would degrade somewhat and would be slightly less. Anyway, 1 gallon of gasoline contains about 33KWH of energy and weighs about 6.5 lbs. 85KWH of energy, “stored” as gasoline, would weigh only 16.5 lbs. Of course, 85KWh of electrical energy can be used much more efficiently than the same amount as gasoline, but when the battery pack is fully depleted, it still weighs 710 lbs! As for the 16.5 lbs of gasoline, well it would weigh zero :bigsmile: 710 lbs of dead weight is a lot to push around.
There are a lot of fundamental problems with totally electric cars and it will be awhile yet, I believe, before they become practical.
BTW, from reading the article, it was the rapid degradation of the cells after successive charges that did Envia in.
This is why I believe hydrogen cars will be the future.
Rapid hardly represents the abysmal performance, they did something like 3 cycles in claimed energy density then plummeted to typical levels closer to 50% of claimed capacity. They essentially offered nothing of practical use.
Beats me why people bang their heads so hard trying to make electric behave like gas, instead of exploiting each for what it does best. For a long trip I want not only serious capacity and easy and fast refills, I want a nice comfortable car that holds all the people and stuff I want. For around town I would be willing to use much more basic transportation like the electric SmartCar that is about $15k and goes 68 miles on a charge.
Even better I would like to see two or three electric vehicles parked within easy walking distance that I could reserve via the net and pay via credit card per use.
and even a racing car 
