ElectricMotorcycleForum.com
General Category => General Discussion => Topic started by: NEW2elec on December 08, 2016, 08:47:42 PM
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Passing this along for your valued opinions as I've wanted to talk about the pros and cons for a while now.
Basically I've heard it breaks down to super capacitors just don't have the energy density of batteries.
But < 1 min charge time pretty much would wipe that argument out. It could be just another over hyped vapor ware story but Brits wouldn't lie, right mates :)
http://www.hybridcars.com/supercapacitor-breakthrough-allows-electric-vehicle-charging-in-seconds/ (http://www.hybridcars.com/supercapacitor-breakthrough-allows-electric-vehicle-charging-in-seconds/)
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You pretty much nailed the worst drawback of supercaps, they're nowhere near the energy density of a good Li-ion battery. Also, they're far more expensive, and their voltage drops linearly as they discharge, unlike a battery. Every technology has its pluses and minuses that have to be dealt with by the engineering team. Besides, there are some pretty impressive claims being made for some new Li-ion technologies, too...but nobody's gotten their snake oil on the road yet. Start selling it, then I'll believe it exists.
But I'm curious how you think a fast charge time eliminates the energy density problem. You're going to have a charging station every five miles, not worried because you'll only have to spend a minute at each one? Good luck with selling that use case, or building that infrastructure.
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I agree get it to market or its just a dream. Their claim of 150 mile range in 1 min would be a game changer though.
I'm looking at a big picture of some logistics issues that will have to be overcome.
One huge one being gas stations. If your going to kill thousands of businesses they are going to fight back hard. If you give them a way to convert to a new way and pretty much keep their business model intact they will come on board.
You have to have sub 10 min charging to work in the same pull up, fill up,(buy coffee and snacks) go model.
How about this:
Fast charge supercaps then use them to charge your batteries like a hybrid that uses supercaps instead of a gas generator to recharge the non linear discharging batteries.
Ok kill that dream now :)
Please note I never feel insulted by being corrected I know I am a novice but I enjoy this stuff and it stretches my silly putty mind.
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I'm killing any spelling bee dreams! You spelled putty wrong!
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Those were dead long ago LOL
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150 mile range on for example a Zero is around 15 kWh of energy, no real way of going around that except for riding really slow or having a much more aerodynamic profile.
to charge 15 kWh of energy in 1 minute requires 15*60 = 900 kW of power !! 900 kW at 100 volts (current Zero batterypack voltage) is 9000 Amps !! I dont wanna know what size of cable is required for that :o . Even if you would crank up the pack voltage to 1000 Volt it would require 900 Amps. and 1000 Volt comes with high risks.
Even worse for a Tesla. 100kWh of energy (current largest sized batterypack) charging in 1 minute is 6 MegaWatt of power. No way the powergrid is ready for that.
Current pack voltage of a Tesla is 400 Volt. 6 MegaWatt at 400 Volt is 15000 Amps !!
The current Tesla supercharger charges at 120 kW or 300 Amps. That's already a very substantial current.
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That's what people forget a lot, it's not only what the vehicle can take but also what the grid can deliver. You can buffer with on site batteries but even then you need beefy regulators and thick cables.
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I think a smart grid and lots and lots of range might be more practical. Let's say you have a vehicle capable of 500 miles range. That's not unthinkable within the next five years. You'll only need that range if going on a long trip or venturing into the unknown. The rest of the time you tell your smart charger at home to maintain a minimum of 250 miles of charge. That's happily around the 40 - 50% state of charge where the battery is under the least stress.
Providing destination chargers are powerful enough to top you up overnight, then having to charge en-route becomes a thing of the past. Or it doesn't become some behemoth like at the service stations. Most people will just stop for comfort.
It's charging anxiety that's the biggest issue for me with my car. Therefore getting rid of it by not needing to charge away from home on all but very rare occasions has to be the best solution.
There doesn't seem to be much money in providing EV charging infrastructure.
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Much of early stage projects going on in this area, there is a district over here where they are experimenting with just that. People who have PV and an electric vehicle can connect their vehicle to a charging station and use it as a buffer.
A power company over here is even running a project where they want to use about 20% of your powerwall's capacity for local net stabilisation, and for that they are willing to shell out €450 per year.
I'm guessing that in the future most roofs will have pv on them and every household will have a modest battery that they can charge on the cheap when it's sunny and windy and use when electricity is more expensive. Or even sell back to the grid at that point.