Anyone ever tried to implement regenerative braking?

[mr_ed]

That's the bi8t you're misunderstanding. It won't. There are no motors with a cable actuated clutch.

When you have an electric car or motorbike, the only way to move is with the motor or by using gravity. A bicycle is moved by pedalling, but that makes people get aching legs, so they want an electric motor to help them. If the motor is engaged all the time it needs to be powered, otherwise it'll create drag. The drag will cause you to have to use more energy to pedal at the same speed, or you can use more power from the motor to overcome it, which cancels out the gain you got from your regen.

I was surprised there were no current motors with an electro-operated clutch so they could truly freewheel and engage for regen as required. I think this could be part of a future motor design with integral regen.

It's the sort of thing university graduates used to come up with after studying about energy saving and green policies, but they have no real-life

Maybe I need to go back to engineering school because I always thought that opening the throttle a little bit causes the motor to use a little bit of power. What would be the point of opening it a bit if it did nothing. You might as well leave it shut.

By throttle I am referring to the pedal. This is how ‘one pedal mode’ works on electric cars, as someone else as posted a diagram of below. The top third of the pedal is regen, then a coast window, then a progressive power application.

Going back to engineering school… could be a good option having seen some questionable project bikes and the problems they’ve had. Surprising given knowledge bettering engineering graduates and the laws of physics.

So, you asked for opinions. We gave you advice based on actual experience. You don't like the answers, so we must be wrong. Is that it? We could have sat here silently, while we exchanged personal messages between ourselves and had a good snigger at your expense.

I listened to your experience based on existing products on the market… however the energy is there to be reharvested rather than wasted and let’s hope better products are available in future that can also do that in a way that suits the rider. You seem unreceptive to that possibility.

Every forum has someone who has to reply to every single thread and thinks they know it all but inevitably they don’t and rather spoil the forum for other people… If someone comes on and asks a sensible question (I’m not suggesting perpetual motion or anything of the sort) and you want to snigger with your gang in private messages, then fill your boots!

Can’t wait to read more about your latest project bike!

 

[Cisco-man]

I’m thinking that a better way, rather than regen, would be a more intuitive way of applying what power you do have from the battery when riding. Admittedly I’ve got fairly basic bikes but I do notice that the power kicks in when I don’t really need it, and doesn’t modulate the power for the ups and downs of a simple road.

 

[jimriley]

I have a kt controller 24a, for the recumbent tandem, it specifies "light regeneration" on the label. I have noticed it kicking in on longer descents when the battery isn't full. It's operated by switched brake lever. Not travelled far enough to fully test it.

 

[mr_ed]

I’m thinking that a better way, rather than regen, would be a more intuitive way of applying what power you do have from the battery when riding. Admittedly I’ve got fairly basic bikes but I do notice that the power kicks in when I don’t really need it, and doesn’t modulate the power for the ups and downs of a simple road.

There are some cool ideas relating to using a tilt sensor to boost power on uphill and reduce it on the downhill. Or a form of cruise control/speed limiter where power assist or regen level is modulated to stick at the desired speed. You could even monitor the heart rate of the rider via a Bluetooth watch etc. It’d be cool to play with all these things and maybe the ebike controller should be an app on the smartphone that has all of these sensors built in that communicates with the motor/battery via Bluetooth. I think I’ve seen one ultra tidy/minimalist ebike where all the controls were via a smartphone app.

Also with satnav on the phone, if you set a destination it could plan where to use the power and to what level to reach your destination optimally. e.g. arriving with the battery at 1%, ramping assistance up on prolonged hills etc.

 

[saneagle]

There are some cool ideas relating to using a tilt sensor to boost power on uphill and reduce it on the downhill. Or a form of cruise control/speed limiter where power assist or regen level is modulated to stick at the desired speed. You could even monitor the heart rate of the rider via a Bluetooth watch etc. It’d be cool to play with all these things and maybe the ebike controller should be an app on the smartphone that has all of these sensors built in that communicates with the motor/battery via Bluetooth. I think I’ve seen one ultra tidy/minimalist ebike where all the controls were via a smartphone app.

Also with satnav on the phone, if you set a destination it could plan where to use the power and to what level to reach your destination optimally. e.g. arriving with the battery at 1%, ramping assistance up on prolonged hills etc.

You really ought to go out and try a load of bikes. We already have some of that stuff - tilt sensors and speed control. They're shite and there are are much simpler and more reliable systems that give you the power you want when you want it, where you have control over it instead of by stupid algorithms designed by people who never actually rode an ebike.. It's great that you guys keep dreaming up new ideas (actually old ideas recycled). Eventually, someone might come up with something useful.

 

[mr_ed]

Ebike trip simulator with optional regen

Thanks... that's really interesting. I'll play with that some more. At first glance, it says there's 49% energy reclaim available through regen on my 20 mile ride to work!

 

[Ghost1951]

There are some cool ideas relating to using a tilt sensor to boost power on uphill and reduce it on the downhill. Or a form of cruise control/speed limiter where power assist or regen level is modulated to stick at the desired speed. You could even monitor the heart rate of the rider via a Bluetooth watch etc. It’d be cool to play with all these things and maybe the ebike controller should be an app on the smartphone that has all of these sensors built in that communicates with the motor/battery via Bluetooth. I think I’ve seen one ultra tidy/minimalist ebike where all the controls were via a smartphone app.

Also with satnav on the phone, if you set a destination it could plan where to use the power and to what level to reach your destination optimally. e.g. arriving with the battery at 1%, ramping assistance up on prolonged hills etc.

Or you could just let the pilot increase the pedal assist level when he noticed there was a hill because his legs were having to work harder. Why make riding a bike more complicated and unreliable? I don't understand. The joy of cycling is that it is such a natural extension of your own body, and the joy of electric assistance is that it takes away some of the hard work when you get older and you can relive your youth - flying up hill.

 

[mr_ed]

Or you could just let the pilot increase the pedal assist level when he noticed there was a hill because his legs were having to work harder. Why make riding a bike more complicated and unreliable? I don't understand. The joy of cycling is that it is such a natural extension of your own body, and the joy of electric assistance is that it takes away some of the hard work when you get older and you can relive your youth - flying up hill.

I take your point, but you could argue using a tilt sensor to automatically keep the assistance in the right ballpark is making riding the bike simpler and meaning you don't have to fiddle with the controls. I guess whatever feels natural. Regarding reliability, I suspect a solid state tilt sensor is probably more reliable than the cheapy mechanical +/- buttons on Chinese e-bike kits!

Just as an aside, automatic gearboxes on cars have tilt-sensors built in and feed these into the gear maps so that they'll hold a lower gear for longer when ascending or descending a hill.

 

[saneagle]

Thanks... that's really interesting. I'll play with that some more. At first glance, it says there's 49% energy reclaim available through regen on my 20 mile ride to work!

You can easily experiment to see if that's true and to see if it's what you want. Get yourself a low KV R/C motor. Mount it on a bracket like a friction drive with a cable and lever to pull it in contact with the wheel. Connect the phase wires to a 3-phase bridge rectifier., then through an adjustable charge controller set to your battery's charge voltage, and connect it to your battery's charge socket. Whenever you go downhill, pull the lever to operate the friction drive, which will charge your battery. If you don't want to make one, there's this ready-made unit.

Pardon our interruption...

 

[mr_ed]

You can easily experiment to see if that's true and to see if it's what you want. Get yourself a low KV R/C motor. Mount it on a bracket like a friction drive with a cable and lever to pull it in contact with the wheel. Connect the phase wires to a 3-phase bridge rectifier., then through an adjustable charge controller set to your battery's charge voltage, and connect it to your battery's charge socket. Whenever you go downhill, pull the lever to operate the friction drive, which will charge your battery. If you don't want to make one, there's this ready-made unit.

Pardon our interruption...

Nope... because that's a bodge solution so a waste of time and I wouldn't have something cobbled together like that on my bike. If you're comparing solutions like this with a proper solution that that perhaps explains your past experiences...

All my discussions have been related to a well engineered solution, fully developed and tested by the manufacturer and with no additional parts so fully integrated within the existing motor/driveline (only exception being different brake levers with sensors).

 

[saneagle]

Nope... because that's a bodge solution so a waste of time and I wouldn't have something cobbled together like that on my bike. If you're comparing solutions like this with a proper solution that that perhaps explains your past experiences...

All my discussions have been related to a well engineered solution, fully developed and tested by the manufacturer and with no additional parts so fully integrated within the existing motor/driveline (only exception being different brake levers with sensors).

Yeah, yeah, yeah. That just about sums you up.

 

[Cisco-man]

Nope... because that's a bodge solution so a waste of time and I wouldn't have something cobbled together like that on my bike. If you're comparing solutions like this with a proper solution that that perhaps explains your past experiences...

All my discussions have been related to a well engineered solution, fully developed and tested by the manufacturer and with no additional parts so fully integrated within the existing motor/driveline (only exception being different brake levers with sensors).

A hashed-together solution in my world is a “Proof of Concept”. You make it professional if and when it works!

 

[Ghost1951]

I still think that no one has seriously considered the idea of having a windmill on the front of the bike. I know some airliners have a deployable wind generator for emergency power which emerges from the bodywork and enables some electric power if all else fails.

Personally, I would keep it in action all the time topping up the battery as I went along. What's not to like about free power? Even better when going into a head wind like I was just now. You could arrive home with more battery capacity than you started out with.

 

[danielrlee]

I still think that no one has seriously considered the idea of having a windmill on the front of the bike. I know some airliners have a deployable wind generator for emergency power which emerges from the bodywork and enables some electric power if all else fails.

Personally, I would keep it in action all the time topping up the battery as I went along. What's not to like about free power? Even better when going into a head wind like I was just now. You could arrive home with more battery capacity than you started out with.

It's not free power! The energy to power the generator has to come from somewhere. Rather than dealing with all the efficiency losses created through energy capture and conversion, why not just use the input energy to power the bicycle directly?

 

[Ghost1951]

 

[saneagle]

You have to try things to see if they work.

 

[saneagle]

I still think that no one has seriously considered the idea of having a windmill on the front of the bike. I know some airliners have a deployable wind generator for emergency power which emerges from the bodywork and enables some electric power if all else fails.

Personally, I would keep it in action all the time topping up the battery as I went along. What's not to like about free power? Even better when going into a head wind like I was just now. You could arrive home with more battery capacity than you started out with.

I already told you, I'm building exactly that for my next project, seriously. I have the perfect generator, so now I need to attach it to the perfect turbine. I'm probably going to go with Ugrinsky type.

 

[saneagle]

why not just use the input energy to power the bicycle directly?

It makes no difference. You might as well put the charge in the battery. It's just a matter of electric charge going in and out. If you're pedantic, you could argue that there are higher conversion losses, but when you're riding along using 200w while generating 250w, who cares.

 

[danielrlee]

Oh Christ! I can't tell who's being serious and who's not now. My fault for getting sucked into such ridiculous conversations....

 

[saneagle]

Oh Christ! I can't tell who's being serious and who's not now. My fault for getting sucked into such ridiculous conversations....

Serious. This vehicle can travel directly into the wind at double the windspeed and directly downwind at three times the windspeed without a battery and without a motor. Counter-inuitive, yes, fake, no.

https://en.wikipedia.org/wiki/Blackbird_(wind-powered_vehicle)