Test1 RedCat Earthquake 8e

[radioman193]

all i can say

Is do testing and you will see the esc has 0 output under breaking.
and look at how the voltage is sent to the motor under breaking.

Under realworld bench testing.
just test a few esc/motor combos on the bench.

I need not say more on this as the proof is easy to find
and dont Overthink and make it harder than it is.

and remember this just because a motor runs on just say 6v @ 3 amps
thats not saying that it will OUTPUT 6v @ 3a as a Generator cause it wont.
so this blows away the number tossing game out the window.

there just might be Some or a few Rc Brushless esc's that do utilise regernerative breaking but i myself have not found one.

just do some Simple testing that others and i can do to see .......
And if i am found Wrong i will drop off ALL Rc forums completely never to post again .

[J57ltr]

Here is some info:

If Patrick said it you can pretty much take it as gospel.

http://www.rc-monster.com/forum/show...=regen+braking

Originally Posted by othello

You will also notice regenerative braking when hooking up an eagletree logger to a car setup.



Driving my truggy on asphalt with a Neu 1512/2Y (1400kv), Jazz 55 ESC and 10s1p A123. I marked the amp and voltage peaks where i applied brakes. The green line represents motor rpms. The eagletree logger records positive Amps (not negative amps) and voltage does rise instead of falling -> the battery is recharged. Amp Peaks around 15-20A with voltage rising by 1.3-1.4V

A similar behaviour can be seen with MMM and BK ESC.

Quote from Pdelcast about MMM EscQuote:
The braking is regenerative because it has to be -- can't dump that much energy anywhere but back into the battery. (The battery is used as a load, but using a battery as a load mean charging the battery...)

It is not, however, optimized.

Still gets fairly good efficiency up to about 35% braking power -- above that the conversion efficiency gets lower.

[J57ltr]

Originally Posted by radioman193

all i can say

just do some Simple testing that others and i can do to see .......
And if i am found Wrong i will drop off ALL Rc forums completely never to post again .

No need to drop of the face of the earth for being wrong. I have been wrong several times. I don’t have a license to be an Electronic Tech, but I do have a degree (as do several others here). Here is a simple test. I am sure you must have a meter that has a peak hold function on it. Strap that on your RC car, turn on the peak hold feature connect to the battery and take it out. Do some hard braking and see what happens.

Jeff

[BrianG]

Originally Posted by J57ltr

No need to drop of the face of the earth for being wrong. I have been wrong several times. I don’t have a license to be an Electronic Tech, but I do have a degree (as do several others here). Here is a simple test. I am sure you must have a meter that has a peak hold function on it. Strap that on your RC car, turn on the peak hold feature connect to the battery and take it out. Do some hard braking and see what happens.

Jeff

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. But really, any value above the battery voltage should indicate regen braking, because any voltage above the battery voltage will cause current to flow from the higher to lower potential, which is from the motor to the battery.

[J57ltr]

Looks like he is only running 4S so it shouldn't be a problem, but thanks for pointing that out.

Jeff