regen as strong as brakes, possible?

cwah

100 MW
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Jul 24, 2011
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Between paris and london
Hello,

I'm trying to have a bike that is as maintenance free as possible, and with normal bike the brakes are wearing down so fast I'm really annoyed by that.

I've heard many compliments about regen performing almost as good as brake... but I've never had any on my hand....


I tried many controllers: lyen, cellman, bmsbattery and other new sine wave ones...


But all of them were somehow set to low regen.... or have blown now.

I have a 7kg dd from leafbike. Is there any controller (2000W) that can allow me to have good braking with regen? It needs to be small and reliable.

Thanks
 
What he said. :)

I use regen on the heavy CrazyBike2 and it does most of my braking for me. But I sitll have to have mechanical brakes for it to completely stop, and to hold my place on the hill.

You *could* setup what's claled Plug Braking, which literally shorts the motor coils, and will work down to basically zero, but it doesn't hold you in place, and the slower you go the less effective it is. For that you would need "active" braking, which is something like the anti-theft option that some controllers have, where they actively fight any rotation of the wheel.

That will use up power, though, whereas regen braking recovers it. Depending on how much you use it and in what situations, you may need to greatly increase the size of your battery pack, possibly by a lot, with such a system.

Presently I don't think any system in production offers this, though it's been discussed in a thread started by John in CR, if you want to hop over there and join in.

http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=62793
 
Doesnt' matter about top speed; problem is at low/zero speeds.


At higher speeds, you can set up a contorller (or buy one that cna be, cuz not all of them do it the same way) for the proper regen braking currents to slow you as needed.

If your battery can't take the regen currents, you would need a battery that could, or some other solution to absorb the braking power, like plug coils around your frame, etc., and a system to switch the controller from batteyr power to the plug coils so the current is shunted to them during brkaing, and then back to the battery when not braking so the motor has power.
 
Ypedal said:
works good at high speeds, but as you slow down the braking effect goes away significantly .. you still need physical brakes if you want to come to a dead stop ... but with this type of use the pads last realllly long.
not true with adaptto. keeps you stopping hard right up to the light. i can use it w/o the pads touching. and i've only got my max regen amps set to like 20A or something. would do higher, but i've not enabled variable regen yet, so it comes on quite hard. there is a smooth mode, but that causes a tiny lag on release. regen does cause the controller to heat up much moreso than w/o running regen.
 
cwah said:
Can you recommend a small controller that can do that? All my previous purchase were a waste of money :(

Wouldn't it be cheaper and easier to just replace brake pads occasionally, instead of cycling through controllers, which will have their lives shortened by the excess heat of regen?
 
My bike weighs over100lbs. I have a Zombiess modified Xie Chang 150v controller set to 60% regen. Braking from 60 mph to 20 is all regen then I use two 203mm disc brakes to stop. Anymore than 60% causes skidding.
 
I use one of Grins Regen Controllers and that seems to save me using my brakes alot less than i did prior but as others have said its great slowing you down at speed but the initial stop must be made with my normal pads.
When i hit my regen at around 50km/h it slows me down quite fast till about 20km/h then you need to use the real brakes to come to a stop. Changing the way you ride might help things by coasting as you approach your stop, I tend to back off the throttle about 100 meters and coast then use my regen to stop the last 15 to 20 meters but in an emergency stop sittuation i wouldnt even consider using regen to stop me fast.
I tend to see around 1100 to 1200 Watts going back into the battery when i 1st hit regen for a few seconds then it slowly works its way down to nothing as i approach the 10km/h mark.
 
Do you use disc brakes? Some disc patterns tend to make the pads wear really fast. If the pattern is too hollowed and looks like cutting edges, its more likely going to make the pads wear out too fast! Here are some examples:

Good pattern rotors:
Central_Lock_out_Bike_Disc_Brake.jpg

51Cdfrnu16L._SL500_.jpg

hs1_160mm_large.jpg




Bad pattern rotors:

bicycle_disc_rotor.jpg

saw_rotor_good_pic.jpg




Of course this isn't 100% accurate, but according to my experience, big holes means fast pads wearing. Small holes improve braking efficiency and keep pads good for longer time
 
With regen I found it sufficed for normal, expected braking, with a light dab of the front disc brake for a complete stop. I only really used the mechanical brake for unexpected braking.

That was with no rear mechanical brake fitted and the Golden Motor controller, for which I recall someone else saying the regen was "almost like plug braking".

Lots of strain on the motor axle flats, though.
 
Punx0r said:
With regen I found it sufficed for normal, expected braking, with a light dab of the front disc brake for a complete stop. I only really used the mechanical brake for unexpected braking.

That was with no rear mechanical brake fitted and the Golden Motor controller, for which I recall someone else saying the regen was "almost like plug braking".

Lots of strain on the motor axle flats, though.
Exactly, my experience with regen.
 
Thanks for all your comments.

What lightweight set up would allow me to do that reliably? Sabvoton & kelly are too big for my need. 2000w peak and 1000w constant is enough for me
 
This is all good reading, along with Justin's thread on regen. I still haven't made up my mind on geared vs direct drive for my next build. I thought I'd settled on a 9C clone, then last week changed my mind to a BPM/CST, now reading this I'm swinging back to the DD. I'm very interested in your build cwah since your requirements are usually similar to mine.
 
Regen will never give you the braking precision of a well tuned brake. Braking precision means shorter braking distance and this is a life saver, so you need good brakes. Then, regen can be a very good help in some situations, on slippery surface, deep mud or snow, etc... This can make your braking distance even shorter in many emergency situations, so it is good to have regen, a must for some who ride fast on various surfaces.

Regen can't replace your brakes safely but it will help, more or less according to your set-up and riding style. It does save on brake pads, but if you abuse of regen the cost of brake pads could very well be transfered on controller repair, tires, suspension pivots, etc... That is why I recommend to set a regen switch that is independent of the brake lever, so you can use brakes and /or regen at will.

Use a brake that has a large braking surface, large pads and large rotors are lasting much longer, cause they spread the force and shed the heat much better.
 
when I was using a chain drive on the 5kw golden motor... Once regen was engaged it actually looked up the rear wheel for a second or so on the road and i had to tone the regen current... it was incredible good with regen due to the chain drive reduction I had.
 
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