2jim1

When you put on the motor controled brakes in an RC car does this feed power back into the battery and charge it a little?

I have a mamba monster and castle 1515Y motor.

Thanks

howtowakeakar

iTrader: (4)

I think you would be running the motor backwards, draining the battery.

drperry

iTrader: (3)

Not enough to really make any kind of a noticable difference.

Keeping the mechanical brakes on a 1/8th conversion will give you longer battery life.

function>form

iTrader: (50)

no it does not charge the battery.... the caps on your speedo retain some voltage but nothin the average driver would feel

Dave H

Tekin 411 series did this in the day. It really helped, especially in 8 minute 12th scale. But then we only had 1400 and 1700 batteries.

Haven't seen it mentioned in any esc literature for quite a while though.

Overunitygreg

I did a test with a clamp type amp meter around the battery wire, and i found the current goes back into the battery when braking.
Hope this helps you all.

Devigili22

iTrader: (29)

Yes it does, slightly. Under braking the motor is basically a generator converting kinetic energy into current.

Theibault

I would love to see KERS in RC. Tekin, Viper, LRP, get on this!

platgof

iTrader: (4)

I nearly burned my battery on a downhiller!

Overunitygreg

My hobbywing 150a esc seems to already have KERS
Must do more testing/setup to get longer run time with my 1/8
Maybe more drag brake

rallyredevo

Autocratic

iTrader: (26)

Considering that the only brakes you have in a brushless system is when the ESC uses electrical current, from the battery, to slow the motor down, any amount of back-feeding from the motor would be cancelled immediately once you applied the brakes.

Coasting, is different, but how often does anyone here allow their car to coast for anything more than a few seconds?

Overunitygreg

How does this explain the current going TO the battery not out when i brake?
The current from my amp meter switches direction AFTER i pull the throttle. This must mean that the drag braking is recharging the battery!
The esc acts like a full wave bridge rectifier [Turns AC into DC].
The motor becomes a generator from the kinetic energy of the moving car.

kufman

iTrader: (6)

This really isn't true. The brakes do not work by using more power from the battery. Worst case is that the power generated by the motor is dissipated in the drive FETs. The tests that I have done on my Castle MMP shows that power is actually going back into the battery.

I haven't found this to be the case. A high torque servo will use 2 or 3 amps worth of current to pull the brakes and the additional weight and rotational mass of the brakes will require more power to accelerate. So really all you are doing is putting more stress on the BEC but you are not saving battery power.

Pulse_

+1 don't see the use of mechanical brakes: more weight, more parts, more complicated, less room, no real improvement.. You can try them but honestly if you're used to electric cars it's not needed