Tailwind - fastest charging electric bike

flecc

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Oct 25, 2006
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No! It's SCiB battery is very low capacity for it's size and weight, developed for fast charge car use and very unsuited to e-bikes. Li-polymer and LiFePO4 are currently the best options by far for e-bikes.

Schwinn are full of gimmicks like this, and again its something we've commented on many times before.
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daniel.weck

Esteemed Pedelecer
Aug 8, 2009
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Li-polymer and LiFePO4 are currently the best options by far for e-bikes.
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Hi Flecc, the newest Brompton Nano kit ships with a LiMnO2 battery (36V 10AHr), which according to the sales department is the best you can get:

"
there is no better (or more expensive) technology currently available than LiMnO2 - which we use - it is best for power per volume and power per weight
"

What is your view on this ?

Thank you very much, this forum provides an invaluable resource for newcomers like me ! :)

Kind regards, Dan

PS: I'm a Brompton MR6+ owner, in the process of securing the purchase of the Nano kit (if only the customer service was a bit more responsive...)
 

Tiberius

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Nov 9, 2007
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What sets the charging time on an e-bike is generally the charger rather than the battery.

Most battery types can be charged in 1 hour (this is called the 1 C rate). But for a 10 Ah battery that means a charger capable of delivering 10 A, which would be a fairly serious piece of kit.

A 2 A charger is smaller, lighter and cheaper and that's what is generally used. Hence the normal 5 hour charge time.

Nick
 

Straylight

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Jan 31, 2009
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But would charging a standard li-ion at a higher rate pottentialy damage the cells?
 

flecc

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Oct 25, 2006
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Hi Flecc, the newest Brompton Nano kit ships with a LiMnO2 battery (36V 10AHr), which according to the sales department is the best you can get:

"
there is no better (or more expensive) technology currently available than LiMnO2 - which we use - it is best for power per volume and power per weight

Kind regards, Dan

Yes, their service is lousy!

There may no difference in what they are saying about the battery, these nomenclatures are all abbreviations. These batteries are all lithium-ion types, but some increasingly use polymer construction and theirs may be. The chemical formula they've given indicates a manganese oxide cathode which has been pretty well standard for the last three years, but the best of the latest supplied batteries are using compound cathodes including other elements. The exception is a type not yet on our bikes as standard but probably soon to be, LiFePO4 (lithium iron phosphate) which lasts at least twice as long as previous types.

You can read a fuller story on this in my post here.
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Tiberius

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Nov 9, 2007
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But would charging a standard li-ion at a higher rate pottentialy damage the cells?
You would need to check for the specific battery, but I would have thought most Li-Ions could take a 2 C charge, ie charge in 0.5 hours.

But, in just the same way as high discharge rates, a high charge rate on a battery not cleared for it may shorten life.

You also have to be even more careful to terminate the charge at the correct point. With a higher charge rate the ensuing event if you don't could be more, well, eventful.

Nick
 

flecc

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Oct 25, 2006
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But would charging a standard li-ion at a higher rate pottentialy damage the cells?
The SCiB battery that the Tailwind uses is specifically designed for very rapid charging. There's no particular magic in this facility, it's very much a matter of cell content density and therefore the cell capacity. For example, lithium polymer was originally developed as a very fast charge battery but was found to to be better in other roles with higher density of cell content.

Short range fast charge batteries like SCiB are irrelevant to e-biking where high capacity with light weight and small size are far more important than having fast charge at the cost of much higher weight and bulk for a given capacity.
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OneWayTraffic

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Apr 7, 2009
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The SCiB battery that the Tailwind uses is specifically designed for very rapid charging. There's no particular magic in this facility, it's very much a matter of cell content density and therefore the cell capacity. For example, lithium polymer was originally developed as a very fast charge battery but was found to to be better in other roles with higher density of cell content.

Short range fast charge batteries like SCiB are irrelevant to e-biking where high capacity with light weight and small size are far more important than having fast charge at the cost of much higher weight and bulk for a given capacity.
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I don't know. If your day involves touring local coffee shops, then you could recharge at every Starbucks!

More seriously, a fast charge is only as useful as the number of times that you're likely to be able to use it, and not have enough time for a longer charge. It makes a lot of sense for personal electronics, that are always with you, but for an ebike most either charge overnight, or charge during their 8 hour shift at work.
 

flecc

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Oct 25, 2006
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from How Will Toshiba's SCiB Battery Technology Impact EVs? - DIY Electric Car Forums

"Toshiba announced Monday in this press release the commercial release of the SCiB (Super Charge Ion Battery). The battery's selling points are that it can recharge to 90% capacity in less than five minutes, it's safe and it has a 10-year lifespan."
Toshiba have been pursuing the fast charge for cars "Holy Grail" for a decade now, seemingly not realising what a dead end it is.

The current in Amperes that a "fuel" station would need to fully fast charge half a dozen cars pulling in within five minutes would require every filling station to have it's own major sub-station with huge transformers fed from high voltage overhead lines from the national grid. We are speaking of thousands of amps of current here, but put another way, the infrastructure to support filling stations operating in this way would be impossible to build and maintain.

Any future electric cars will have to put up with slow charging however inconvenient that is, but there will still be a need for our power stations to be multiplied in large numbers to charge them even then.

One day Toshiba will wake up to the facts.
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Mussels

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Jun 17, 2008
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The National Grid can't cope too well at the moment, loads of people just slow charging their cars will bring brown outs.
 

JohnInStockie

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Nov 10, 2006
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Toshiba have been pursuing the fast charge for cars "Holy Grail" for a decade now, seemingly not realising what a dead end it is.

The current in Amperes that a "fuel" station would need to fully fast charge half a dozen cars pulling in within five minutes would require every filling station to have it's own major sub-station with huge transformers fed from high voltage overhead lines from the national grid. We are speaking of thousands of amps of current here, but put another way, the infrastructure to support filling stations operating in this way would be impossible to build and maintain.

Any future electric cars will have to put up with slow charging however inconvenient that is, but there will still be a need for our power stations to be multiplied in large numbers to charge them even then.

One day Toshiba will wake up to the facts.
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Or maybe they will realise a method to swap batteries at all filling stations, althoug I doubt it!
 

Patrick

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Feb 9, 2009
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The current in Amperes that a "fuel" station would need to fully fast charge half a dozen cars pulling in within five minutes would require every filling station to have it's own major sub-station with huge transformers fed from high voltage overhead lines from the national grid. We are speaking of thousands of amps of current here, but put another way, the infrastructure to support filling stations operating in this way would be impossible to build and maintain.

Any future electric cars will have to put up with slow charging however inconvenient that is, but there will still be a need for our power stations to be multiplied in large numbers to charge them even then.
It wouldn't necessarily have to come over the national grid, if you had a battery with a power density similar to petrol then it could be used to deliver the electricity to the filling stations by road in much the same way as petrol is as the moment. I doubt this is anything near feasible yet but it's an intriguing idea.

One possible use I see for a fast charge battery in cars is that if you had a fast discharge battery at home then that could be slow charged from the national grid and used as a reservoir to fast charge the car.
 

NRG

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Oct 6, 2009
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Isn't it best to use a small high efficiency ICE engine to charge the battery if the need arises out on the road and have the main charging cycle as a 'slow' overnight one?
 

flecc

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Oct 25, 2006
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It wouldn't necessarily have to come over the national grid, if you had a battery with a power density similar to petrol then it could be used to deliver the electricity to the filling stations by road in much the same way as petrol is as the moment. I doubt this is anything near feasible yet but it's an intriguing idea.

One possible use I see for a fast charge battery in cars is that if you had a fast discharge battery at home then that could be slow charged from the national grid and used as a reservoir to fast charge the car.
Isn't it best to use a small high efficiency ICE engine to charge the battery if the need arises out on the road and have the main charging cycle as a 'slow' overnight one?
There's virtually no hope of a battery reaching petrol power density of course, so a dead end where existing needs are concerned. The secondary battery method would work but would be both inefficient and expensive. Better to use the swap battery method that John mentions and which Renault are already building for trials in an Israeli scheme, and of course that doesn't need fast charge anyway.

As said, fast charge is a dead end which has very little application, hence Toshiba letting Schwinn use it in a totally unsuitable application. Seems like an act of desperation to me, trying to recover something from a decade of useless research.

NRG's solution is somewhere near right at present and already used twice. It's on the Chinese BYD car which is electric for moderate journeys and switching to it's petrol engine for drive on the odd long trip over about 80 miles. It's also on the Chevrolet Volt electric car which runs primarily on electric but as the battery runs low it's petrol engine starts up and charges the LiFePO4 battery while still running on electric.
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