Power Capacitors?

I've read some places that a capacitor installed across the battery pack can help on accelleration. The logic being that the batteries' iR is limiting the amount of current that can make it to the motor. Supposedly, the cap provides a much needed high-current boost while also cushioning the initial load on the batteries when launching from a stop.

In theory, I can see it working, but only with a lot of capacitance. I'm thinking your run-of-the-mill disposeable camera flash capacitor might barely be enough to affect anything, but bigger would be even better.

Has anyone heard more about this, or tried it? If so, what kinds of capacitors are people using?

[broke ess supra]

you are right about the capacitors giving a boost at the start. This is only if the internal resistance of the capacitor is really low
(ESR). Axial capacitors are the ones you want to get since they have really high capacitance and are about twice the size of a hearing aid battery.
Photo capacitors don't do anything they actually don't work they have a really high internal resistance...plus they're really big
i used to know site that had caps but lost the link why don't you search for it

[HBDrummer4god]

Hey, I'm selling capacitors for $9.00 a piece. The yare 1 Farad capacitance at 5.5 Volts. You solder them onto the motor leads so when you turn the car on, the cap charges and when you hit the gas, it releases all that energy really fast. Go to this site if ur interested. http://www.pizzaboxmeeting.org/XMod/Xmod_Heat. Thanks. Email me at Xmod_Heat@yahoo.com if you have any questions.
Doug

[Horshu]

Is this capacitor intented to be connected at the positive battery lead? I've been thinking about putting a cap port on my ESC for a while, but two things held me back: 1) person I ordered my caps from ripped me and about 40 other people off, and 2) I could never actually find specific instructions for where to put it.

[HBDrummer4god]

Hey dude, well the way you would connect the capacitor is you put the positive leade, to the positive end of the battery, and the negative end to the negative end of the battery. The capacitance is 1 Farad and the Resistance is 30 Ohms. at 1 kHz frequency. I think the Xmod has less frequency than that, so it would be a lower resistance.
Doug

[Horshu]

Ahh, perfect...I designed all my battery harnesses to be chainable, so I should just be able replace the terminating connector with the cap (you can also do neat stuff like add in one or more extra battery packs or insert temperature measurement devices, etc, but I'm very glad the generic daisy-chain allows for a NOS to go in)

[HBDrummer4god]

Hey I'm still performing tests on the capacitors, but would u be interested in them?
Doug

I sell caps CHEAP!!

http://search.ebay.com/_W0QQsassZblindpandaQ5feric

Team Novak sells power capacitors for ESC's.
There's some info on how they work at their Tech Info page: What is a POWER CAPACITOR? .
The actual capacitors are sold at: Team Novak Store

Originally posted by crazytom
Team Novak sells power capacitors for ESC's.
There's some info on how they work at their Tech Info page: What is a POWER CAPACITOR? .
The actual capacitors are sold at: Team Novak Store

Tons less powerfull, and alot more money.

Mine are better!!

http://search.ebay.com/_W0QQsassZblindpandaQ5feric

Maybe if you wanna use it on an aftermarket ESC. But even the higher grade racing ESCs only require ~8-10,000 uF.

Originally posted by crazytom
Maybe if you wanna use it on an aftermarket ESC. But even the higher grade racing ESCs only require ~8-10,000 uF.

Thats what they require, you can use alot more. For instance, 1,500,000 micro farad, it works like a dream, tons better then the 47,000.

[dark_wing]

Could I use this 5.5V power capacitor if I wanna use Lithium (7.2V or more)? Thanks

You could, but it would not work right, and there would be many problems. I don't sugest you do so, the liions provide enough power.

[dark_wing]

And what is better Li-Ions or Li-Pos?