Regen x 2

[1-track-mind]

I sense that regen is generally regarded as being on the short end of the benefit/cost analysis, but I wonder if that would still be the case in a dual drive set-up ? Also wondering if terrain factors into the equation.

 

[Drunkskunk]

terrain factors in. going down hill and using regen for a drag brake is the best use of regen.


Regen works by converting the whole bike's kenetic energy into electric. your amount of kenetic energy is fixed by your weight and speed. having 2 regenerating motors means they will each take half, but since each has a certian amount of loss, your doubling part of the inefficancy.

 

[pwbset]

Hi again 1-track-mind.. it seems that all the things you're interested in are the same things I was a few years ago. Check the thread link below where I experimented with regen during a 1,600ft decent that's the "heading home" leg of my commute... in a nutshell regen is neat, but I don't use it today since a) the return isn't all that great and b) unless you're running a really "slow" motor like a 4013 at low voltages (which would necessitate a series/parallel setup) you'll need all the regen specific controller gear/ebrakes etc. and, to me, the extra complexity and possible points of failure just weren't worth it. I don't like breaking down in the woods/mountains miles from home. :wink: Instead I turned all that potential regen energy into a resistive brake that slows me down with the motor and saves my v-brake pads a ton of wear and tear.. figure not having to replace v-brakes all the time is way more economical than saving a few pennies with regen.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=6553

As always.. just my .02.

 

[pwbset]

Reading Drunkskunk's post I realize that with the right gear you'd get regen and ebraking.. duh.. my bad.. I was coming at it from the most simplistic approach of regen'ing by going over no load speed where you don't get any (or very little anyway) braking effects. I'd still argue that the added complexity and cost wouldn't really be worth it, but to each their own.

I never claimed to be smart.. :wink:

 

[dogman dan]

Regen's effectiveness for extending range is said to be 10-15%. Given the length of the ride and the up and down route, regen may be well worth it to you. Regen is a bust for me, since I ride down the hill with a full battery. My house is on the top, and work is in the valley.

I believe that the new infineon controllers at Ebikes-ca would make a regen setup easy. One big problem with regen has been that the lifepo4 bms's can't handle the reverse flow, but if you are going to use lead, you should be ok to use regen. You could use a combination of lifepo4, along with sla's, and put the regen into the sla's.