Brompton Kers (kinetic energy recovery system)

[Goater]

There is an article in the Guardian today about Brompton's move into electric bikes. Interesting enough but what caught my eye was this paragraph:

The new bikes employ pedelec technology, which stores energy from pedalling and releases it when the rider reaches a hill. The Brompton system has been developed in partnership with Formula One team Williams and is a slimmed down version of the Kers (kinetic energy recovery system) technology that racing cars use to gain extra speed.

Perhaps the misunderstanding/misuse of the term 'pedelec' suggests a general lack of comprehension on the part of the journalist and things aren't quite as reported? Alternatively, have Brompton really hit upon the 'Holy Grail' of electric biking: a bike that charges (at least partially) via pedalling? Can anyone shed any light on this?

Article in full: https://www.theguardian.com/business/2016/may/30/brompton-hopes-electric-bikes-power-international-growth

 

[RobF]

Interesting stuff, although I see production models are still due 'next year'.

Brompton have been saying that for five years or more.

This time, it does look like we will finally see a factory eBrompton - sometime.

 

[Benjahmin]

If the battery is charging from the pedals being turned then that's going to feel like pedalling through treacle. A 2Amp charger, at 230V, is using 460watts and takes 3-4 hours to charge a 15Ah battery. How many watts, over and above that needed to just move the bike, can an average rider produce? Not anything significant methinks. Unless Brompton have finally cracked perpetual motion, I think this is a non starter.

 

[KirstinS]

Something doesn't add up. Suspect journo error

Kinetic energy isn't electric energy

Either it is true kers (doubtful)

Or it's just regenerative braking. Which is a waste of time/money. Just makes overly complex bikes for very little gain

 

[KirstinS]

Interesting stuff, although I see production models are still due 'next year'.

Brompton have been saying that for five years or more.

This time, it does look like we will finally see a factory eBrompton - sometime.

I wanted to buy a cytronex kit some years back. I email them every new year to see how it's going......it and the e Brompton have been the epitomy of vaporware to date !

 

[shemozzle999]

The rear wheel looks like it is powered but the pedals are stationary........oops!

 

[oldgroaner]

There is an article in the Guardian today about Brompton's move into electric bikes. Interesting enough but what caught my eye was this paragraph:

The new bikes employ pedelec technology, which stores energy from pedalling and releases it when the rider reaches a hill. The Brompton system has been developed in partnership with Formula One team Williams and is a slimmed down version of the Kers (kinetic energy recovery system) technology that racing cars use to gain extra speed.

Perhaps the misunderstanding/misuse of the term 'pedelec' suggests a general lack of comprehension on the part of the journalist and things aren't quite as reported? Alternatively, have Brompton really hit upon the 'Holy Grail' of electric biking: a bike that charges (at least partially) via pedalling? Can anyone shed any light on this?

Article in full: https://www.theguardian.com/business/2016/may/30/brompton-hopes-electric-bikes-power-international-growth

This sounds like the journalist or Brompton themselves have misunderstood what an E bike actually does, you need assistance when pedalling, not to charge a battery to help you up a hill.
Surely they haven't simply used the motor as a dynamo?
They cannot be that stupid surely?
Or can they?

 

[Goater]

I looked up KERS (never heard of it before) and apparently it's using kinetic energy generated when braking to generate and store electrical power:

https://en.m.wikipedia.org/wiki/Kinetic_energy_recovery_system#

So it's not pedelling which charges the battery but braking. Interesting to see his much power can be generated on a bike like that and also to see how heavy the KERS unit is.

Seems a bit implausible to me but the journo won't have made up the KERS part of the story so, er, fingers crossed...

 

[oldgroaner]

I looked up KERS (never heard of it before) and apparently it's using kinetic energy generated when braking to generate and store electrical power:

https://en.m.wikipedia.org/wiki/Kinetic_energy_recovery_system#

So it's not pedelling which charges the battery but braking. Interesting to see his much power can be generated on a bike like that and also to see how heavy the KERS unit is.

Seems a bit implausible to me but the journo won't have made up the KERS part of the story so, er, fingers crossed...

Regenerative braking is already applied on some bikes certainly Trek have one that has this feature so it isn't all that new.

 

[fishingpaul]

I have had a fair few people ask me,if the battery charges when you pedal your bike,and even seem surprised that you have to charge it from the mains,so probably a complete lack of understanding by the journalist.

 

[anotherkiwi]

Or Williams engineers, or Brompton... or all three

 

[Tomtomato]

This sounds like the journalist or Brompton themselves have misunderstood what an E bike actually does, you need assistance when pedalling, not to charge a battery to help you up a hill.

Maybe you have misunderstood why most people need an electric bike for: mainly provide assistance when going up a hill, as opposed to cycling on flat roads...

If someone could create a bike that charges itself (with minimum resistance/drag) most of the time, to provide assistance in short boosts (so small battery = small additional weight), then it could be very interesting indeed.

 

[oldgroaner]

Maybe you have misunderstood why most people need an electric bike for: mainly provide assistance when going up a hill, as opposed to cycling on flat roads...

If someone could create a bike that charges itself (with minimum resistance/drag) most of the time, to provide assistance in short boosts (so small battery = small additional weight), then it could be very interesting indeed.

Frankly it would be a complete waste of time no matter where you live, as if you live in a flat area you would not benefit, conversely in a hilly area the amount you could contribute to the battery between hills wouldn't get you ten yards, would it?
Have you any idea how fit you would have to be to put a useful amount of charge into a 36volt battery?
Quite simply you would have to be so athletic you wouldn't need the system!

 

[flecc]

Maybe you have misunderstood why most people need an electric bike for: mainly provide assistance when going up a hill, as opposed to cycling on flat roads...

If someone could create a bike that charges itself (with minimum resistance/drag) most of the time, to provide assistance in short boosts (so small battery = small additional weight), then it could be very interesting indeed.

It can never be practical, the effort needed on the flat to generate even a trifling amount is very high. I've watched a number of attempts using stationary bikes or pedalling devices to generate current for low demand systems like lighting and the cyclist(s) involved get exhausted in minutes.

Continuously generating worthwhile charge current for our motors while riding on the flat is beyond any one average cyclist's ability, and for obvious reasons e-bikes are most frequently used by those of less than average cycling ability.
.