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    When will electric car batteries improve?

    Electric car batteries are very poor. If you hook up to a 50kW charger, then you will only charge at 50kW if you are completely flat…as soon as the battery voltage picks up (which doesn’t take long), the charge rate goes down to a few Kw ‘s at best. (it must go down otherwise the battery voltage soars too high) So when will this problem be solved?

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    Re: When will electric car batteries improve?

    Which car/battery are you referring too? A BMW i3, 18.8 kWh LiIon battery charges to 80 % in less than 1/2 h.

    See http://www.bmw.com/com/en/newvehicle...ical_data.html



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    Re: When will electric car batteries improve?

    Maybe that is when they are blowing fans over the battery etc. (ie lab conditions) ..because I am reliably told that no electric car on the face of the planet earth can charge that quickly in real conditions....because the battery voltage goes up and the charger has to peg back the charge rate.....trust me, this is the case with Nissan Leaf, and nobody would buy Nissan leaf if the i3 could charge at 50kw, when the leaf can only go up to a few kw's with its battery.
    I am told this by someone in the EV car indusry who has a Nissan leaf and takes it to the ikea 50kw chargers and it goes well below 50kw. This mans boss owns an i3. So he would know.
    50kw is marketing hype.



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    Re: When will electric car batteries improve?

    I'm willing to believe the manufacturers specification in this point more than guesses and information from hearsay. It's also not obvious that a "50 kW charger" has 50 kW power available when you connect to it, even if the car battery can take it.

    I must confess that I don't have much information about the Nissan car, there are many details affecting charging behavior, e.g. does the battery have liquid cooling, is it activated during fast charging?

    Generally, I don't contradict the viewpoint that batteries are still the bottleneck of electromobility. Useful temperature range, lifetime or price are even more a problem than charging speed and energy density, I believe.


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    Re: When will electric car batteries improve?

    Why would anybody want an electric car today? Even though gasoline price is mostly taxes it is cheap and there is enough available for the rest of my life and maybe for the life of my kids. My grandkids might be driving electric cars maybe 30 or 50 years from now. Diesel fuel is a stinking smoking joke on this side of the pond.

    The Li-Po batteries for my electric radio controlled model airplanes charge at high current quickly without getting hot. They get warm when discharging at a very high current.
    The Battery University.com says, the charging is constant current until the battery reaches its maximum allowed voltage then the charger switches to constant voltage and the battery (not the charger) reduces the charging current as the charging finishes. Maybe the BMW electric car (I have never seen one) does not let the battery finish charging.


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    Re: When will electric car batteries improve?

    they wouldn't be able to sell Nissan leafs if the i3 was capable of 50kw charging.

    - - - Updated - - -

    Very soon the entirety of uk will be electric, because it allows us to save power stations by "vehicle to grid" energy ethos. Also, it relieves our dependency on middle eastern oil. As we know from recent tragedy, dependency on mid east oil is not good.....cars will use less energy because people wont use them so much because they run out of charge and take long time to charge, so there'll be less "sunday drivers" packing the roads out like it is now in uk.



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    Re: When will electric car batteries improve?

    Price is everything. Audioguru, maybe gasoline in Canada is dirt cheap but my local station charges (converting to $CDN) $2.82 per liter at the moment. Thats a lot of money to some people, including me. But then I pay even more per liter for 'stinking smoking' Diesel because it gives me more km/L. No, it isn't a Volkwagen before someone makes jokes about emissions! Nor have I ever seen any smoke come from the exhaust.

    Electric vehicles are a way forward, if only because it's possible in many cases to generate or at least subsidize the cost of electricity. Charging points are still rare here and that holds their popularity back, my nearest is about 80Km away so by the time I charged it and got home it would need charging again!

    Treez, if you pumped a constant 50KW in to a battery, and it reached full charge ( you seem to be suggesting that would be the ideal case until full charge was reached) where would the remaining power go as it 'filled up'. 50KW of heat ?

    Brian.
    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
    It's better to share your questions and answers on Edaboard so we can all benefit from each others experiences.


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    Re: When will electric car batteries improve?

    I meant that the charge rate pegs back long before full charge is reached.....this is my gaffer talking, and he owns a Nissan leaf and he goes to ikea 50kw chargers and he gets only a few kws rate of charge for most of the time on it. He says all batterys are the same like this. He works in EV cars...he races EV cars too. He is electronics eng.

    - - - Updated - - -

    In Formula E they have huge iron transformer chargers which slam charge in at 22kw’s when the Electric car comes in for pitstop. –Note they don’t do 50kw (because its not possible , as discussed) …..what you don’t see when viewing is the numerous battery fires that happen in the pits because these “slam” chargers keep slamming charge into the battery even when its severely overvoltaged (they don't peg back the charge rate, for obvious reasons, your in a race)…..the media get ushered out of the pits as soon as batteries start smoking so that they can’t report it…..all done because they don’t want them “ kopping a load of battery fumes” when the pit staff are right over it breathing it in and feeling fine.

    So when we getting 50kw's?



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    Re: When will electric car batteries improve?

    In Canada about 1/3rd of gasoline cost is taxes (less than I guessed before). Most gasoline has 10% ethanol (from corn) in it and I do not think it is taxed yet.
    Today, regular gasoline is $1.02 Canadian per liter. Last time I filled up a couple of weeks ago it was $.90 Canadian because gas stations had a price war. Here, money grows on trees but it is difficult to reach.
    Do you charge your electric cars at an Ikea Scandinavian furniture store?



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    Re: When will electric car batteries improve?

    There was long time ago that I heard about researches on cheap and flexible batteries which could fill unused spaces, probably acting with more than one purpose ( e.g acoustic/thermal isolation ).


    However, no more noticed any further mention of that. This kind of product could act as an additive power to the current Lead-acid/Lithium based technologies, increasing the overall performance of the vehicle, giving the ability to other parts to store energy.
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    Re: When will electric car batteries improve?

    Quote Originally Posted by treez View Post
    If you hook up to a 50kW charger, then you will only charge at 50kW if you are completely flat
    Although this drops quickly as charging continues, the advertisers quote the max amount as a selling point. That way it's not entirely dishonest. Nevertheless as you said, market hype.



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    Re: When will electric car batteries improve?

    Local Ikea store here in uk has "50kw" chargers.
    In Canada about 1/3rd of gasoline cost is taxes
    UK is now owned by Canada, so I hope ours drops to 1/3 soon.....Mark Carney, Canadian, is in Charge of the Bank of England. UK is the only country in the world to have a foreigner in charge of its National finances...not that I am complaining, Carney is a good guy, I hope he stays in the post.



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    Re: When will electric car batteries improve?

    The Battery Univesity.com says, the charging current stays at the maximum allowed current until the battery voltage reaches its maximum allowed voltage then the battery is about 70% fully charged.
    Some Li-Po batteries (ThunderPower brand) for model airplanes can charge at 5 times their ampere/hour rating so are fully charged in 1/5th of an hour (12 minutes).



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    Re: When will electric car batteries improve?

    Thanks, but with electric car batteries, the battery gets up into overvoltage well before its anywhere near 30% charged, and the charger then needs to peg back, to a few kw's at most. Its just the chemistry, it can't take fast charging except under lab conditions.



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    Re: When will electric car batteries improve?

    The big problem with any ultra fast recharging, regardless of battery chemistry is rapid temperature build-up in the battery, and in some cases even catastrophic thermal runaway.

    Nobody likes exploding batteries, and the higher battery energy densities go, and the more reactive the chemical processes become, the more potentially dangerous it all seems get.

    The future may well be in the direction of pumped electrolyte cells, where replacing the magic fluid in the vehicle's storage tank effectively fully recharges the vehicle battery capacity.

    So instead of filling up with ten gallons of unleaded gas, you fill up with ten gallons of magic battery electrolyte. And it should be almost as quick to refill.
    The magic electrolyte could then be safely recycled in bulk by some possibly fairly slow (and safe) electrical regeneration process.

    Research into this has been ongoing for decades, and is only now starting to show some progress.
    Not there yet, but if it can be perfected I feel that is the future, not only for vehicles but bulk alternative energy storage.

    Thing about how a small 3Kw battery could be hooked up to a vast storage tank that could store and recharge hundreds of Kw hours of fluid, how that might revolutionise wind and solar power industry.
    Cheers, Tony.


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    Re: When will electric car batteries improve?

    Ni-MH cells get hot when charging. Ni-Cad batteries get cooler when charging then get hot when over-charging (try charging a Ni-Cad and a Ni-HH at the same time and feel them).
    Lithium cells charge at 99 percent efficiency so do not get warm unless you are seriously cramming in too much current. My lithium model airplane batteries charge fairly quickly and do not even get warm.
    But they get hot when discharging very high current. The wiring, connector and speed control circuit also get hot at high current.



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    Re: When will electric car batteries improve?

    It all depends on the quality and surface chemistry of the Li-Ion battery that one uses, the very best ones can charge at 5C (i.e. 5 times the nominal Ahr rating) however, you do get internal dendritic growth under these conditions.
    We have 50Ahr cells, prismatic Li-ion-Phosphate of reasonable quality but we don't charge them higher than 50A (1C), a one hour recharge rate - they don't get at all warm, and can easily supply 400A under discharge.



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