# Ebike charging



## Biker man (6 Jan 2022)

Toyota hybrid charges it's self so why can't this technology,be applied to ebikes.Technology is doing fantastic things so why not ebike charging.


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## ebikeerwidnes (6 Jan 2022)

Not sure what you mean
Do you mean regen braking so that going downhill or stopping at lights puts extra charge into the battery?

or something else?


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## si_c (6 Jan 2022)

"Self Charging" Hybrid cars are a joke, they get a little bit of power from regenerative braking, but mostly they just charge a battery from the engine, which is about as efficient as you'd imagine.

For regenerative braking on a bike you'd need to use a hub drive motor system which is less efficient than a crank drive, and overall there would be little benefit for lots of additional complexity and weight.


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## fossyant (6 Jan 2022)

Ho ho, you'd have to pedal a bit harder to charge your batteries if you needed self charging.


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## fossyant (6 Jan 2022)

si_c said:


> "Self Charging" Hybrid cars are a joke, they get a little bit of power from regenerative braking, but mostly they just charge a battery from the engine, which is about as efficient as you'd imagine.
> 
> For regenerative braking on a bike you'd need to use a hub drive motor system which is less efficient than a crank drive, and overall there would be little benefit for lots of additional complexity and weight.



Quite. Why Toyota did a hybrid Yaris, when the engine only one can do 60 mpg ? SIL's Prius isn't that 'efficient'.


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## classic33 (6 Jan 2022)

fossyant said:


> Ho ho, you'd have to pedal a bit harder to charge your batteries if you needed self charging.


Pedal or find a decent hill.


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## fossyant (6 Jan 2022)

classic33 said:


> Pedal or find a decent hill.



Come on, it's an ebiker we're talking about here.


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## the snail (6 Jan 2022)

It wouldn't be difficult to do - just tow a petrol generator behind you in a trailer?


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## fossyant (6 Jan 2022)

TBH, the bike would be even heavier with some sort of re-generative braking.

Battery technology really needs to be improved, it's still pretty rubbish.


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## ebikeerwidnes (6 Jan 2022)

I read an article about this sort of thing a year or two ago - hence no link
But anyway - what it said is that it is possible to make an efficient motor and it is possible to make an efficient generator
but it is not easy to make an efficient motor than is also an efficient generator if you push it backwards

Hence - to get regen braking and charging on downhills then, if you want it all from the one system, you can only have the motor OR the genny being efficient.
And, in any case, it turns out that the extra power that you manage to push into the battery is minimal.


TBH I have answered this sort of question many times on other sites - although it is normally someone who has worked out that if you have a rear drive ebike and put a dynamo onto the front wheel then you create an ebike that charges itself and never needs to be plugged in
either that or they want to mount a small solar panel on the rear rack to do the same thing.

At least the OP makes more sense than this!!!

The article I mentioned above was written some time ago.
SInce then I have seen some ebikes that have regen - but they tend to be small companies or start-ups and next time I look they have gone

so maybe the technology has advanced and we are nearly there!


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## classic33 (6 Jan 2022)

ebikeerwidnes said:


> I read an article about this sort of thing a year or two ago - hence no link
> But anyway - what it said is that it is possible to make an efficient motor and it is possible to make an efficient generator
> but it is not easy to make an efficient motor than is also an efficient generator if you push it backwards
> 
> ...


https://intermountainbikes.com/which-electric-bikes-have-regenerative-braking/


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## classic33 (6 Jan 2022)

fossyant said:


> Come on, it's an ebiker we're talking about here.


You go up one, you tend to have one to go down as well.


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## the snail (6 Jan 2022)

fossyant said:


> TBH, the bike would be even heavier with some sort of re-generative braking.
> 
> Battery technology really needs to be improved, it's still pretty rubbish.


I think the technology is pretty good. I can get 50-100 miles on a charge, which is plenty for me, and most people I suspect. If I was still commuting, I could easily do a week on one charge. I think the only situation where I would struggle would be long distance touring or audaxing, but I don't do those sort of rides anymore. For my use, the technology is plenty good enough.


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## fossyant (6 Jan 2022)

classic33 said:


> You go up one, you tend to have one to go down as well.



There are only up's round here - what's this mythical 'downhill'.... or that's how it feels.


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## ebikeerwidnes (6 Jan 2022)

classic33 said:


> https://intermountainbikes.com/which-electric-bikes-have-regenerative-braking/


Thanks - you are clearly someone who can be bothered to spend 2 minutes on a search engine

I was apparently in a 'can't be bothered' mood but I suppose I should have looked it up myself first

looks like a decent article


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## figbat (6 Jan 2022)

Toyoyta’s “self-charging hybrid” position is largely a marketing ploy to try and make the most of Toyota putting their resources into conventional hybrid technology whilst many others pushed the PHEV angle, which comes with genuine range benefits.


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## classic33 (6 Jan 2022)

fossyant said:


> There are only up's round here - what's this mythical 'downhill'.... or that's how it feels.


Here be one





A steady descent


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## cougie uk (6 Jan 2022)

Biker man said:


> Toyota hybrid charges it's self so why can't this technology,be applied to ebikes.Technology is doing fantastic things so why not ebike charging.


Please tell me you don't really think that the hybrid charges itself ? How ?


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## ebikeerwidnes (6 Jan 2022)

cougie uk said:


> Please tell me you don't really think that the hybrid charges itself ? How ?


Yup - it does
The idea is that energy that would be used in braking and then gets dumped into the atmosphere as heat is converted into battery charge - which can then be used to power the motor - instead of petrol.

Ok - not much - but some


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## cougie uk (6 Jan 2022)

ebikeerwidnes said:


> Yup - it does
> The idea is that energy that would be used in braking and then gets dumped into the atmosphere as heat is converted into battery charge - which can then be used to power the motor - instead of petrol.
> 
> Ok - not much - but some


That's an absolutely tiny amount. 

They're 'self charging' in that you fill them with petrol and the engine charges up the very small battery. 

My electric car also has regen but you still have to charge it. 

I think there's a lot of people confused by hybrid technology.


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## ebikeerwidnes (6 Jan 2022)

In theory they are more efficient overall - in spite of having to carry around an extra motor and batteries

Of course - it also depends on how you drive them - looking ahead and braking gently and early generates power to be used when you pull away again
Braking at the last minute and hard still use the normal brakes and generates heat as usual.


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