Capacitor as a battery

jeffdawgfan

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Ok, I have to admit that my background is in nuclear mechanical engineering and not as an electrical engineer. But a question that perplexes me that maybe someone can shoot down. Electrical capacitors can be charged very very quickly. Why couldn't a large capacitor be used instead of a battery in a vehicle. I know capacitors discharge like instantly but it looks like that circuits could be designed that would slow this discharge down to a reasonable level. Capacitors don't need Lithium, and really don't care too much about ambient temperatures seen by a vehicle.

The reason I have been thinking about this was I was thinking about what we used to do in shop in high school. We would charge capacitors and throw them at each other. It would hurt like hell when they hit you and discharged. Amazing I even survived to my age all the stupid crap we used to do.
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ChasingCoral

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Ok, I have to admit that my background is in nuclear mechanical engineering and not as an electrical engineer. But a question that perplexes me that maybe someone can shoot down. Electrical capacitors can be charged very very quickly. Why couldn't a large capacitor be used instead of a battery in a vehicle. I know capacitors discharge like instantly but it looks like that circuits could be designed that would slow this discharge down to a reasonable level. Capacitors don't need Lithium, and really don't care too much about ambient temperatures seen by a vehicle.

The reason I have been thinking about this was I was thinking about what we used to do in shop in high school. We would charge capacitors and throw them at each other. It would hurt like hell when they hit you and discharged. Amazing I even survived to my age all the stupid crap we used to do.
https://interestingengineering.com/...replace-batteries-in-future-electric-vehicles

An important application being considered is for that last 20% of SOC. While charging the battery to 80%, also charge the supercapacitor. You then use the capacitor first to drive and top up the battery, then get to the rest of the battery.
 
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jeffdawgfan

jeffdawgfan

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Just finished reading article. Thanks, Mark. Guess for now will just have to charge those capacitors and throw them at my grandkids as they can't power my EV........:D
 

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They’ve been working on a technology for years called supercapacitors. Sort of the holy grail of electrical storage. Here’s an interesting problem to consider though: even if they do manage to create practical supercapacitors that can store the amount of energy required for an EV, in an appropriate form factor and weight limit, and hit a cost target, how do you deliver the amount of energy required to charge them in the short period of time required? How do you deliver, say, 88 kWh in 5 minutes or less? I’ll let the electrical engineers with backgrounds in high power distribution explain this challenge (I know it’s difficult). Now, suppose you have 4-5 vehicles at a charging station trying to refuel at the same time (and before you say “that’s a totally unrealistic scenario!”, let me take you to my super-Wawa some weekday evening around 6:00 PM, when you’ll see vehicles filling up at most of the 16 pumps). Now, you’re delivering close to 1 MWh of power to a location every 5 minutes! Wow!
 


Jimrpa

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Pretty cool, but the supercapacitor isn’t being used as a primary storage mechanism. In a way, it’s very roughly analogous to turbo-charging, or super-charging an internal combustion engine, in that you’re recovering otherwise wasted energy and dumping it back into the propulsion system (I know that’s a very tortured analogy). I’d love to see the problem of light weight, high, capacity, very fast charging energy storage, along with the infrastructure to support it solved ? Nuclear Diamond Batteries anyone? ?
 

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You could probably run a really fabulous riverboat with such a batacitor. Maybe even two riverboats. (My apologies if you were never Philip Jose Farmer fans.)
 
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jeffdawgfan

jeffdawgfan

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You could probably run a really fabulous riverboat with such a batacitor. Maybe even two riverboats. (My apologies if you were never Philip Jose Farmer fans.)
I remember reading that series years ago. Wonder what Mark Twain would think of our electric wagons.......I forgot what they found when they finally got to the misty tower at the end.
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