does drag brake use up any battery power? - RC-Monster Forums

blueb8llz · **does drag brake use up any battery power? -** 06.11.2008, 08:31 PM

i currently have my drag brake off, but if i set it to 10%, will i notice a slight decrease in runtime since instead of coasting (which uses no battery) now its applying some brake. also what are the advantages and disadvantages to having a drag brake set.
to me one advantage is, i liked it how on brushed motors it wont coast that long..and the disadvantage would be for jumps...it will prollly bring my nose down.

BrianG · 06.11.2008, 09:07 PM

That's odd. Usually, the ESC sorta dumps the energy from the motor EMF back into the battery thereby increasing runtime.

The only thing I can think of is that the drag brake is slowing down the truck enough where you need to apply more power to go again as opposed to coasting.

MetalMan · 06.12.2008, 12:19 AM

Quote:

Originally Posted by BrianG

The only thing I can think of is that the drag brake is slowing down the truck enough where you need to apply more power to go again as opposed to coasting.

Exactly what I was thinking. The return from the drag brake back into the battery is less than the equivalent amount of power required to get back up to the speed you were at before the drag brake kicked in.

blueb8llz · 06.12.2008, 04:05 AM

i dont think you guys understood my thread correctly, i was just simply asking if i had my drag brake set to like 10% or higher, would i notice a decrease in runtime vs drag brake turned off.
and whats the goods and bads having drag brake set to 10% vs no drag brake at all.

hoovhartid · 06.12.2008, 05:23 AM

Quote:

Originally Posted by blueb8llz

i currently have my drag brake off, but if i set it to 10%, will i notice a slight decrease in runtime since instead of coasting (which uses no battery) now its applying some brake. also what are the advantages and disadvantages to having a drag brake set.
to me one advantage is, i liked it how on brushed motors it wont coast that long..and the disadvantage would be for jumps...it will prollly bring my nose down.

I understand why there was confusion...
let me rewrite your thread for you....

i currently have my drag brake off.
if i set it to 10%, will i notice a slight decrease in runtime ?
I was thinking it would because instead of coasting (which uses no battery) now its applying some brake.
also what are the advantages and disadvantages to having a drag brake set.

__________________________________________________ ____________

They thought you actually WERE losing run time.

__________________________________________________ ____________

If I understand their answers correctly...
You should see some INCREASE in run time.

The brake actually takes unused energy back from the motor and puts it into the batteries during braking.
--brian can explain this better i'm sure...or correct me if i'm wrong

blueb8llz · 06.12.2008, 06:15 AM

thanks for rewording for me hoov. yea sounds like i wont be getting a decreaes in runtime if what they say is true. i guess theres no real plus or minus to having drag brake set other than personal preference. sounds more like a hassle cus i hear having drag brake on will give you nose dives when doing jumps....which i already have probs now with drag brake off. i know its just simply adding more throttle in midair, but im always afraid i maybe still hitting the throttle when i hit the ground , which is a no no.

BrianG · 06.12.2008, 09:58 AM

Oops, I guess I read the thread a little too quickly. I read it as "I am experiencing decreased runtime with the dragbrake vs none". The post was maybe a tiny bit misleading, but not unreadable. My bad.

Anyway, any braking should increase runtime slightly as most BL ESCs use regenerative braking.

If you are already nosediving on jumps with no brake, adding drag brake will most likely make it worse. You could try shifting some weight to the rear. Also, if the rear springs are too stiff, they could be throwing the rear end up as it leaves the jump.

GO-RIDE.com · 06.12.2008, 11:51 AM

Drag brake is generally used with 2wd on slippery tracks where trying to apply the brakes manually will often lead to a spin out. At my local indoor track many drivers use a lot of drag brake to slow the car for corners and weight the front wheels for better turn in. Then you have to throttle through the corner to keep the rear of the car from spinning out. As for 4wd I don't find the drag brake to be as neccessary because 4wd brakes much straighter. Also, drag brake and 4wd leads to a lot of nose dive off jumps.

As for run time, I wouldn't expect to see much difference with only 10% drag brake if you are running on a track. What you are probably noticing is that you can drive a bit harder with drag brake because you can hold the throttle on longer into a corner and then the car turns quicker so you can get back on the throttle sooner.

blueb8llz · 06.12.2008, 05:17 PM

got it! thanks for the reply guys, made my decision to not have drag brake turned on. obtw, thanks for the tip about having my rear suspension too stiff which may lead to nose dives, the rear has the exact setup as the fronts, so maybe now ill take a spacer out from the rear so its not as stiff as the fronts.
but from what i hear, most people run stiffer suspension in the back ...at least stiffer shock oil.

06.12.2008, 08:02 PM

Cool, i hardly ever use my brakes, but since it regenerates power to the battery, i might start slowing down for the nitro guys

to lengthen my runtime

.

Sammus · 06.13.2008, 03:58 AM

It could be interesting, not taking a dig at you (although it could be taken that way - please dont :)), but why dont you just give it 10% drag brake for a day out and see how you like it, instead of asking everyone else what they do? It's not like advice on buying motors/batteries that costs you 100s and 100s so you want to know your getting bits that are suited to your purpose.

And re the shocks, hard springs and soft oil is a bad combo in my book, under dampened = very bouncy on the back end makes it harder to control, to each their own though I guess.

blueb8llz · 06.13.2008, 04:07 AM

no offense taken..nah the point of this initial thread was just to see if having the drag brake on will decrease my run time. and for opinions from people that are more familiar with using this feature for the pros and cons. like i said, i know its pretty much personal preference so i was just going to try it out myself but decided i wont need to mainly cus of the nose dive thing. and you guys are all prolly gonna hate on me for saying this, but i dunno...for some reason, i found it somewhat of a hassle getting into the reciever box of my 3905 emaxx and setting up the castle link. sometimes i think about just not using the box and having the reciever in plain site so its easy access. but i know once i have my settings down, its done with no more playin around. its fun but a hassle for me haha

Sammus · 06.13.2008, 05:21 AM

Yeah I know what you mean.. same with my revo radio box... everything is stuffed in there it takes me about 20mins to get all the wires crammed back in properly :P

johnrobholmes · 06.13.2008, 07:06 AM

Right on so far, the drag brake is regenerative and turns the motor into a generator with the battery as the load.

blueb8llz · 06.13.2008, 04:21 PM

dam 20 mins. thats longer than how long it takes me haha. yea my box is packed as well. i have the revo y connector because my fm radio is only a 2 channel and i am still using 2 servos. if your box is the same as mine, theres a hump on the top part of the reciever box, instead of craming everthing neat and nice, you can just have all the wires placed ontop of your reciever...just align the wires to be placed under the hump.