Saying goodbye to batteries
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If design mimics the structure of a chemical battery (lithium) and theory/simulations predict similar energy capacities, then let's get some major funding and start producing iterations of this device. Have several teams working simultaneously to perfect and bring this device to market.
It's tiring to continually hear about these advances coming in 5-10 years. The big 3 automakers should fund the project along with government match dollars. Each company gets equal rights to the patent technology. Let's move !!
The car manufacturers are continually saying the problem with electrics are the batteries. If they're serious about building electrics
then support this development to replace the problematic chemical battery! This even answers the concerns about lithium supplies, safety, country of manufacture, etc... Go Go GO!!life cycle of the battery
Even better, let's plan from the start the entire life cycle of the battery. Doubtless Volt owners will go through more than one battery during the life of the car. Making the battery have a long number of cycles in its lifespan is very important, but let's plan for affordable replacements _and_ recycling the old batteries safely right from the get go.
The days of simply throwing things away are rapidly growing distant in our rear view mirrors. Let's make this next generation of cars clean in all aspects.
Even better, let's plan from the start the entire life cycle of the battery. Doubtless Volt owners will go through more than one battery during the life of the car. Making the battery have a long number of cycles in its lifespan is very important, but let's plan for affordable replacements _and_ recycling the old batteries safely right from the get go.
The days of simply throwing things away are rapidly growing distant in our rear view mirrors. Let's make this next generation of cars clean in all aspects.
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4,087 Posts
I though caps "leak" their charge when just sitting around, so the best approach is a cap buffer, with enough capacity to handle regenerative breaking, and a battery pack to hold the charge much longer.
Lightning in a bottle?
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More like a grenade shoved under your seat.
http://www.youtube.com/watch?v=aWf-V2-kr9Q&feature=related
How large and powerful would a capacitor have to be in order to be practical as a replacement for the batteries in a Volt?
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265 Posts
EV UltraCapacitor?? Big promises.
There are some fantastic claims being made for UltraCapacitors. What would be required to replace the Volt's battery?
It depends on how much of an energy margin,voltage variation, and reliability that is required. We need 8 kWhr of usable energy to match the energy from the Volt's battery @50% charge depletion. We would need a DC - DC converter to regulate the cap's voltage to some voltage, Vreg= 320V, for the motor. The converter probably has a 90% efficiency and would be big and expensive. High voltage power devices are expensive. We need some capacitor energy margin. Lets use 2X. If we extract half of its energy = 8 kWhr from it, the capacitor voltage will drop by 78%.
That meets the energy requirement. We need sufficient reliability to match the battery's 150,000 mile warranty. We may need a 20% higher cap voltage spec for reliability. We still don't know its reliability over charging cycles. Then we have the problem of leakage at high field intensities: how long would it hold its charge. EEstor claims an enormous energy density of 1 MJ/kg. It uses a very high voltage ~ 3400V to get the high energy density. At this voltage, the capacitance for 16 kWhr would be ~ 10F. The cap would weigh ~ 10 kg. How would you charge it to 3400V from your 120V line? Very carefully. There are some nasty liability issues here. But it holds the potential of extending mileage range at reduced weight.
There are some fantastic claims being made for UltraCapacitors. What would be required to replace the Volt's battery?
It depends on how much of an energy margin,voltage variation, and reliability that is required. We need 8 kWhr of usable energy to match the energy from the Volt's battery @50% charge depletion. We would need a DC - DC converter to regulate the cap's voltage to some voltage, Vreg= 320V, for the motor. The converter probably has a 90% efficiency and would be big and expensive. High voltage power devices are expensive. We need some capacitor energy margin. Lets use 2X. If we extract half of its energy = 8 kWhr from it, the capacitor voltage will drop by 78%.
That meets the energy requirement. We need sufficient reliability to match the battery's 150,000 mile warranty. We may need a 20% higher cap voltage spec for reliability. We still don't know its reliability over charging cycles. Then we have the problem of leakage at high field intensities: how long would it hold its charge. EEstor claims an enormous energy density of 1 MJ/kg. It uses a very high voltage ~ 3400V to get the high energy density. At this voltage, the capacitance for 16 kWhr would be ~ 10F. The cap would weigh ~ 10 kg. How would you charge it to 3400V from your 120V line? Very carefully. There are some nasty liability issues here. But it holds the potential of extending mileage range at reduced weight.
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Those liability issues are probably what is going to kill the concept. Sure, someone voluntarily removing himself from the gene pool by screwing around with the ultracapcitor on his 2012 Volt is one thing. Stupidty breeds as much as it kills.
But the second we have ol' Grandma Milly get into an accident that causes the ultracapcitor to discharge all at once and electrify the entire vehicle, thereby turning her into an electrified (and probably smoking hot and/or flaming) granny, they'll deem the vehicle a death trap.
To me, it seems on the same level as putting a 10,000 PSI tank of Hydrogen into the back of a car. HELLO, HELLO! THINK MCFLY, THINK! Lets put the equivilent of the Hindenburg on the back of every vehicle in America, really get that Hydrogen economy into full, explosive force!
To me, just based on that fact, and that we use just as many fossil fuels to create the freaking Hydrogen as it would take to power a gasoline ICE, make it a pipe dream. Of course, it also made a convienient way for the Administration and Big Bussiness to look like they were "getting green" in mid 00's.
Now at least GM realizes we aren't going to realistically wean ourselves off of gasoline for a long time, but can try to make a vehicle that significantly uses as little as possible. They were also smart on choosing E-Flex, since it could accept any sort of fuel, so long as the generator used it, whether it's gasoline, ethanol, biodiesel, regular diesel (I'd kill to have my S-10 be a diesel, I'd convert it to Bio in a heartbeat)...even a blasted Hydrogen fuel cell, if need be.
It just seems funny to me, the railroads have been using this concept (sans battery power) for the last 70 years, and the automotive industry is just now catching up.
But the second we have ol' Grandma Milly get into an accident that causes the ultracapcitor to discharge all at once and electrify the entire vehicle, thereby turning her into an electrified (and probably smoking hot and/or flaming) granny, they'll deem the vehicle a death trap.
To me, it seems on the same level as putting a 10,000 PSI tank of Hydrogen into the back of a car. HELLO, HELLO! THINK MCFLY, THINK! Lets put the equivilent of the Hindenburg on the back of every vehicle in America, really get that Hydrogen economy into full, explosive force!
To me, just based on that fact, and that we use just as many fossil fuels to create the freaking Hydrogen as it would take to power a gasoline ICE, make it a pipe dream. Of course, it also made a convienient way for the Administration and Big Bussiness to look like they were "getting green" in mid 00's.
Now at least GM realizes we aren't going to realistically wean ourselves off of gasoline for a long time, but can try to make a vehicle that significantly uses as little as possible. They were also smart on choosing E-Flex, since it could accept any sort of fuel, so long as the generator used it, whether it's gasoline, ethanol, biodiesel, regular diesel (I'd kill to have my S-10 be a diesel, I'd convert it to Bio in a heartbeat)...even a blasted Hydrogen fuel cell, if need be.
It just seems funny to me, the railroads have been using this concept (sans battery power) for the last 70 years, and the automotive industry is just now catching up.
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265 Posts
Boom!
The amount of energy in the Volt battery is 50 Mega Joules. The explosive energy of a hand grenade has about 200 Joules. 50 MJ is enough to accelerate a 200 lb person to 2500 mph. It is equivalent to 30 lbs of dynamite. This much energy doesn't have to explode to cause problems. Loose test leads, screws, aluminum foil, screwdrivers can be deadly. A one ohm short can result in 3000 amps. This can easily fire up to thousands of degrees and start a fire. A lower resistance path can also vaporize a conductor, initiate, and eject a ten thousand degree plasma flash. I can imagine what a trial lawyer could do with this info.
Remember Murphy's law is compulsory. You may have a low probability event, but if you have a million EVs getting charged one or more times a day. Eventually ... boom!
The amount of energy in the Volt battery is 50 Mega Joules. The explosive energy of a hand grenade has about 200 Joules. 50 MJ is enough to accelerate a 200 lb person to 2500 mph. It is equivalent to 30 lbs of dynamite. This much energy doesn't have to explode to cause problems. Loose test leads, screws, aluminum foil, screwdrivers can be deadly. A one ohm short can result in 3000 amps. This can easily fire up to thousands of degrees and start a fire. A lower resistance path can also vaporize a conductor, initiate, and eject a ten thousand degree plasma flash. I can imagine what a trial lawyer could do with this info.
Remember Murphy's law is compulsory. You may have a low probability event, but if you have a million EVs getting charged one or more times a day. Eventually ... boom!
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How many MJs are in a tank of gas? Exactly:
Casualties in Fire Crashes
From 1975 to 1988, over 1,600 people per year died in vehicles involved in fire crashes. The number of fire-related fatalities has increased over the 14-year period, from 1,300 in 1975 to over 1,800 in 1988, due primarily to the increase in fire rate for passenger cars.
Slightly more than 4 percent of all occupant fatalities occur in fire crashes. For passenger cars, the rate is just under 4 percent, and for light trucks, the rate is 5 percent.
Over the same period, total estimated occupant casualties in fire crashes involving cars and light trucks, annually, are:
http://www.nhtsa.dot.gov/cars/rules/regrev/Evaluate/807675.html
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638 Posts
More deaths (gas) means no media coverage because it is too common to worry about reporting. Two deaths due to electricution per year is news worth and could be a problem. People aren't logical.
Stalin was was well aware of that fact.
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