Regenerative Braking

[Hillbilly]

This YouTube review of electric bikes is now apparantly 3 years old now but includes reference I think to the third bike having regenerative braking. I've used the search facility on this forum without it finding any reference on this so starting this thread. I'm new to electric bikes and live in hilly area so the ability to recharge my battery on the move would be a great boon. Has there been much development on this factor can you get much range back.
Electric Bikes | Fully Charged - YouTube
https://www.youtube.com › watch

 

[flecc]

It's been tried many times, but usually with little success. The big disadvantage is the to regenerate means no internal freewheel, which means drag whenever cycling without power. That's at all times when over 15.5 mph of course. That makes it very unpopular. Regen recovery rates on bikes is poor anyway, due to the low weight and speeds involved. There simply isn't enough kinetic energy to recover much.

Direct Drive motors which inherently have no freewheel make a better case for regeneration, and the Direct Drive BionX motor has four switched levels of regen.

Panasonic tried a variation, a front hub motor which was also a full electric brake with no other on the front wheel since such brakes can be very effective. They launched a large number of these in Japan to try them there first, but it seems to have died since nothing has been heard in the over three years since.
.

 

[(NoLongerRegistered#15675)]

The study I found( which I cant now) suggested at best regen on ebikes would produce around 10% more range, whereas with cars its of order 20 to 25 %. Basically with pedelecs it appears if you want a little more range its more efficient ( well easier) to simply install a larger capacity battery.
Speaking to a chap with ,I believe, a Raleigh Motus with hub dynamo for regen who assured me he got better range with it "switched off" ....
Having said all that I do agree OP has a point.
I often spend over an hour going down hill applying brake throwing energy away ??? Does seem wasteful and gets discs hot !!??

 

[Hillbilly]

OK thanks guys - I presumed there must have been a difficulty if it hadn't become more common by now. I remember the old dynamo lights that used the wheel rotation to generate enough elect to light a tiny bulb, but I suppose the trickle charge generated isn't enough to regen the battery.
I know you can get tiny inverters that plug into the cigarette lighter on your car and allow a three pin to be inserted, obviously you don't want to blow a fuse or flatten you battery but wonder whether you recharge your battery whilst car on the move.
Also I have an Outlander PHEV which in Australia and Japan allows you run electrical apparatus on campsite from the car's 12kwh battery,( but not UK model). I think my ebike battery only has about 0.4 kWh capacity so think it should be possible to transfer the juice somehow. A spare battery would be possible answer if they were a bit cheaper (£190 for my model)

 

[(NoLongerRegistered#15675)]

I have a little inverter and wondered same.ie charging from car. Forums ( and read somewhere on here) that it was ok but asked dealer and he said not. His explanation was that you cant get true sine wave small inverters ( I thought you could) and voltage wasn't accurate enough ???
He reckoned wasn't worth risk on a £500 battery, suppose he had a point..suspect when bike is older I,ll try it ??!!

 

[anotherkiwi]

There is an interesting story on a French velomobile site by a guy in Switzerland. His ride to work is all downhill and he uses regen mostly to be able to stop because without it he fries his hub brake pads (too steep for disks a set of pads doesn't last one trip!!!). So he as to remember to not charge his battery fully when he gets home because then he has had problems with his BMS...

Of course he has to ride a 30 kg velomobile back up the mountain every evening and he is at the limit of the energy his battery can provide.

This is a very extreme situation and it works for him, if you have some Alps handy give it a try!

 

[Deleted member 4366]

If you want to use an inverter, you need one at least 500w. It would need proper wiring to the battery because 500w would blow the fuse in the cigarette lighter.

A much better approach is to get a small generator. these ones are pretty good - very light and quiet:

http://www.ebay.co.uk/itm/DIGITAL-PETROL-GENERATOR-SILENT-SUITCASE-950W-2-year-warranty-over-3000-sold-/381597732372?hash=item58d8ff4e14:m:mdAWCYetrwKGKKw6zjuslAA

 

[Hillbilly]

The Japanese version of my car seems to come with inverter as standard - may look into having this fitted.
Also it seems there are these +'s & -'s of regen which I need to look into

https://www.electricbike.com/regenerative-brakes/

 

[Emo Rider]

The BH Neo range had regenerative braking. Slightly touching the brake levers would turn the rear hub motor into a dynamo. Having the regen system did not impact the performance of the bike when the brakes were not applied, no drag from the motor. It was only 5 to 20% efficient according to BH's info. Having a bit of ability to recharge while riding can't be a bad thing. I did ride the Neo City and know a few whom still own them. Lovely bike.

 

[Deleted member 4366]

The BH Neo range had regenerative braking. Slightly touching the brake levers would turn the rear hub motor into a dynamo. Having the regen system did not impact the performance of the bike when the brakes were not applied, no drag from the motor. It was only 5 to 20% efficient according to BH's info. Having a bit of ability to recharge while riding can't be a bad thing. I did ride the Neo City and know a few whom still own them. Lovely bike.

That's not true. The Neos had a display that was presumably designed for bikes with regen, so a symbol came on the display saying "regen" when the brake was applied, but no regen was possible because the motor had a normal clutch. They used normal Bafang motors. I'm not sure what the situation with their latest bikes is since they changed to the new motor, but I'd be surprised if it's a DD motor for regen.

 

[Emo Rider]

That's not true. The Neos had a display that was presumably designed for bikes with regen, so a symbol came on the display saying "regen" when the brake was applied, but no regen was possible because the motor had a normal clutch. They used normal Bafang motors. I'm not sure what the situation with their latest bikes is since they changed to the new motor, but I'd be surprised if it's a DD motor for regen.

Not true? I truly respect your words and advice on here but I did not make this up. I rode and felt this in action. BH sold them as such. If it were not the motor creating the drag, what then? Tomorrow, just by timely chance, a customer is bringing one in for service. I shall investigate why you think I am incorrect. Perhaps I am and have been mislead . Cheers

 

[Deleted member 4366]

Bafang BPM or CST motor with a clutch. Trust me, regen is impossible.

Report back what you find. Spin-up the motor wheel in the air, apply the front brake so that "regen" appears on the display, and see what happens to the free-wheeling rear wheel.

 

[flecc]

The BH Neo range had regenerative braking. Slightly touching the brake levers would turn the rear hub motor into a dynamo.

Perhaps it was placebo regeneration.
.

 

[Hillbilly]

Not true? I truly respect your words and advice on here but I did not make this up. I rode and felt this in action. BH sold them as such. If it were not the motor creating the drag, what then? Tomorrow, just by timely chance, a customer is bringing one in for service. I shall investigate why you think I am incorrect. Perhaps I am and have been mislead . Cheers

It seems you both may be right ( or wrong). A Google search brought me back to this thread on this forum. ( edit although for some reason the link didn't work - basically it seems BH had regen braking in some years but not others on the same model.
http://www.pedelecs.co.uk/forum/threads/storck-raddar-multitask-se-v-bh-emotion-neo-xt

 

[flecc]

It seems you both may be right ( or wrong). A Google search brought me back to this thread on this forum. ( edit although for some reason the link didn't work - basically it seems BH had regen braking in some years but not others on the same model.
http://www.pedelecs.co.uk/forum/threads/storck-raddar-multitask-se-v-bh-emotion-neo-xt

Try ths link instead, it may be the thread you mean:

http://www.pedelecs.co.uk/forum/threads/storck-raddar-multitask-se-v-bh-emotion-neo-xtrem-my-personal-experience.12604/page-3#post-188406
.

 

[Emo Rider]

It seems you both may be right ( or wrong). A Google search brought me back to this thread on this forum. ( edit although for some reason the link didn't work - basically it seems BH had regen braking in some years but not others on the same model.
http://www.pedelecs.co.uk/forum/threads/storck-raddar-multitask-se-v-bh-emotion-neo-xt

The Neo I worked on today did not have regen in spite of the symbol lighting up on the dash when the brakes were aplied. Kudos to Flecc and D8veh for steering us straight.

 

[SteveRuss]

If you want to use an inverter, you need one at least 500w. It would need proper wiring to the battery because 500w would blow the fuse in the cigarette lighter.

A much better approach is to get a small generator. these ones are pretty good - very light and quiet:

http://www.ebay.co.uk/itm/DIGITAL-PETROL-GENERATOR-SILENT-SUITCASE-950W-2-year-warranty-over-3000-sold-/381597732372?hash=item58d8ff4e14:m:mdAWCYetrwKGKKw6zjuslAA

Any idea how quiet they are compared to the Honda EU range? I'm sort of in the market for one but can't justify the price of the Honda for my occasional usage.

 

[Deleted member 4366]

I have one. It works perfectly. I also have a Honda EX650, which is much heavier and noisier, though it's an older one.

When I'm at the boatyard, several guys there have the latest Hondas. Mine is much quieter. It's the low weight that gives it the best advantage.

 

[Cyclezee]

It's been tried many times, but usually with little success. The big disadvantage is the to regenerate means no internal freewheel, which means drag whenever cycling without power. That's at all times when over 15.5 mph of course. That makes it very unpopular. Regen recovery rates on bikes is poor anyway, due to the low weight and speeds involved. There simply isn't enough kinetic energy to recover much.

Direct Drive motors which inherently have no freewheel make a better case for regeneration, and the Direct Drive BionX motor has four switched levels of regen.

Panasonic tried a variation, a front hub motor which was also a full electric brake with no other on the front wheel since such brakes can be very effective. They launched a large number of these in Japan to try them there first, but it seems to have died since nothing has been heard in the over three years since.
.

The Heinzmann Direct Power (direct drive) motors have a regen mode with 3 levels.
It is only of real value if you ride in a very hilly area.
http://www.ebike.heinzmann.com/en/systems/directpower/motor#

 

[Roderick Read]

I have used a Falco hxm http://www.electricbicycleworld.com/build/
On the very hilly Isle of Harris and throught much of Europe. Steep hills are essential for regen. It's knackering if you set it to regen level 5, you notice nothing but a heavy bike on level 0, I tow my kids along easily with the torque.
I only bought it for regeneration. I spin the crank by kite! http://www.instructables.com/id/Enjoy-a-nice-cup-of-kite-powered-tea/?ALLSTEPS