radioman, i think you are thinking of brushed motors. brushless motors do not have the same style brakes and instead, send the energy back to the battery. i have seen enough eagletree graphs to know this.

also, patrick del castillo, the owner of castle creations even stated himself that most, if not, all brushless escs use regenerative braking.

btw, we don't want you off the forums, we just want you to not take it personally when you are wrong and know that we all make mistakes. i used to argue that my 8-cell ni-mh batteries could put out more power than 2s lipo. now i know better.

Ok so I figured I would give it a try. My setup doesn't lend itself to this type of testing, but it at least shows that it does work.

I used my Rustler running a MMM and a Fine Design 6 turn slotless 2 pole motor, 2S2P A123 battery. Braking isn't very good, and the added weight of the DMM didn't help. The meter I use is a Fluke 112 DMM. The battery pack was not fully charged it was as I pulled it from the drawer.

to add to what scarletboa said^^^^

i've been all over the net, and Rc-Monster was not only there at the beginning of the brushless movement, but continues to be at the cutting edge of technology.

People don't assume things here. We either state fact or say "IMO" (in my opinion)

Nobody wants you to leave, but you were wrong. You owe us a video of your earthquake puddle skipping.:yes:

Im almost certain that brushed esc's use regenerative braking as well. Not sure how the old mechanical speed controls had brakes, but i remember they did....or at least the ones i had had brakes

ok cool
but even on my scope i MYSELF show no positive voltage peaks or spike even under full 100% breaking force.
but Even going by all the chatter on this EVEN if it does the voltage is VERY little back to the battery and if a lipo can only take a 14v @ 5c Max charge rate or 2.2 amps ......
and the Motor under breaking puts out lets say 31v @ 10amps for that time just were do you think that is all going?????
that Aint dumping into the battery over 97% is shunted to ground otherwise the battery life would be very short and would mess up the ballance up quite badly.
so in going just by this alone would make the regernerative breaking conversation Moot for rc cars as the regernerative breaking power Back to the batteries would not charge them Enough to even consider being a regernerative system........

and yes i only run 4s on the Xerun 80A
and a 2230Kv motor

and yes paralyzed if we get more rain here as we did yesterday you will have your "puddle skipping" video but you wont see smoke like your hoping for. as the esc has been tested under water a few times now :mdr:

we're arguing semantics now. The bottom line is that power goes back to the batteries, which you assumed didn't happen.

We've given you several links with factual data showing that power does indeed go back to the batteries. The MGM one in particular describes why insufficient batteries can kill an esc during braking.

We even informed you that Patrick Del Castillo (Castle Creations namesake and chief engineer) is a forum member here and has written us a technical explanation of how castle esc's use regenerative braking.

If you won't read and learn from the links, and refuse to believe what the person who makes esc's says, then there is no point discussing anything with you.

Can you at least admit you are making assumptions based on your prior knowledge, and that you really aren't sure what you're talking about? Because I am sure, if I'm not I preface my statements with, "I think" or "IMO".

"we're arguing semantics now. The bottom line is that power goes back to the batteries, which you assumed didn't happen."

and I DONT off this esc and full 100% breake force as i said.

and as
brianG has said

"I have to add that some ESCs, such as the MMM, do have a TVS device which limits the amount of peak voltage generated during hard braking. IIRC, it's rated somewhere between 26 and 28v, which means that any voltage peaks above its rating are essentially shunted to ground. This means that you might not truly measure the full voltage peak potential."

and on testing THIS esc and motor from Full throttle to Full 100% breake forced by a 12v window motor here on the bench and on a scpoe there is 0 peaks 0 voltage spikes back from the esc to the batteries i even tryed at one time a 20a diode inline the hot of the esc so power will ONLY flow ONE Way and still got 0 on Breakeing testing eather side of the diode i did get all kinds of voltage drops on breakeing with or without the diode.
im not saying thay are wrong im just saying in the case of THIS esc it Don't.
i will test the vxl3s tomarrow and see what i find on that one.
I in no way have said thay are full of crap or that thay dont know what thay are talking about.
just think it just might not apply to ALL esc's or configurations and cause one manufacture has one or some that do one thing does not mean its in stone that ALL other manufactures build or design theres the same way ......
alot of things just might apply to this
Eg
input voltage
cell count
motor kv
esc design
and alot more Im just saying i dont see it here on My bench all i can go by is wht i see happen when i force the motor to spin at 500 rpm under 100% force all that happens is o return voltage and a Hot esc..... oh and a Very HOT window motor that is driving the brushless motor that is trying to stop turning.
the ONLY spike or Peak voltage i have found is the voltage that is there in between throttle and breake the "deadzone" and that is only the battery recovering from the voltage sag from throttle and when you hit the breake it sags again as voltage is applyed to the motor for breaking ..... and in that SHORT short period in between the two "throttle and breake" might LOOK like a return voltage but is not its just that 2ns of time the esc has no load on the battery.


as i Have said before
Im not saying nobody is Wrong or full of crap
but i AM saying that i cant produce the facts that i am wrong and have tryed for over 15 hours of on and off testing of this
and 5 sets of lipos in need of charging badly LOL

and with a little luck and some more rain i will have some wet rc videos to post up tomarrow

Good nite and God bless .

fair enough. Castle esc's and mgm esc's have regenerative braking per the manufacturer.

this is in opposition to your blanket statement that esc's were simple unlike hybrid cars.

Just understand that people know what they are talking about here on RCM. We don't suppose or assume things. That's why I come here. If you open your mind you can learn a lot from the members here, and nobody will lead you astray.

Looks like I am going to have to set up my own test about this and get some pics (or maybe a video) of it. I know it happens, I've seen it. I guess part of it is understanding how it works so you can reproduce it. Although, it obviously won't be in a running vehicle, so results won't be completely realistic.

It seems to me if you are going to bench test this you would probably want to swing a flywheel to get any kind of results. I had to get the truck up to top speed to get the result I got. It took a few tries, and another thing I noticed was that if I hit the brakes that when I watched the meter the voltage would climb faster when I came to a stop than if I was to just coast to a stop. This would also further support that the battery was somewhat being charged when the brakes are used.

Jeff

in a rc or not it will work the SAME
its not hard to add a load to a motor usen a 12v motor on a 12v battery.....

both breushless motor and the brushed 12v motor running the Same direction
then when you hit the breake on the brushless motor the Brushed motor will try to keep it from stoping and or add drag ALOT longer than if it was in a rc.
and is a constant and repeteable over and over.

and my esc is a Xerun 80A-R the black one.

paralyzed

" this is in opposition to your blanket statement that esc's were simple unlike hybrid cars. "

in a hybrid cars regenerative braking is usefull and is setup to regulate the regenerative braking voltage and charge with it.
and i do have an open mind thats why i tested my esc like i have ....
cause if it had regenerative braking i could use that for a few things that i would have liked to try.


if it did have regenerative braking the Thread would have went a completely different direction like check this out ..????????..
and its usen the egenerative properties of the esc.
but that was not the case here.

If memory serves me correctly someone did a test that showed regen effects by using the tekno electri clutch with mech brakes and then swapping in a regular pinion and using motor brakes. They had longer runtime with the pinion and motor brakes, indicating regen braking was recharging the battery somewhat.

My understanding of motor braking was that the esc placed a load on the motor during braking, as opposed to the vehicle placing the load on the motor during acceleration. Maybe to simplified, but with DC current it has to flow one way or the other. I do not see a method to "ground" it out, as it is a closed system. No wire leading to the dirt. Unless you attempt to disapate the braking force into heat, like a mech brake does.

oh paralyzed it did not rain here last nite .......
but i just might still be able to find some fair sized puddles for today....

i am putting the esc and motor back in the RedCat in about 10 minutes from now and the batteries are all charged up ready to go i just need to reprogram the esc before taking it out first .......
then its time for "splash down"

I created another page on the calc site to explain regen braking using Arct1k's formulas he posted earlier: http://scriptasylum.com/rc_speed/brake_power.html

I'd really like to add exactly how much charging current is achieved, but not sure about those formulas, so it's pretty basic right now (hence the beta status).