Wiring Cap pack parallel to ESC wires?
 

Hello,

Seeing the discussion about ripple voltage, and seeing that it is bad for your ESC, I want to re-install my cap pack to my Mamba Monster 1.
The previeus owner installed it in the spot where you can see the heat shrink, where the BEC wires go to also:

http://i1219.photobucket.com/albums/...y/IMAG0725.jpg

But I removed it because it didn't fit because I use a fairly big battery ( Gens Ace 5000mah 45C 6S ), it would stand upwards, and I had to force the body one the posts.
Now here comes the question, is it possible to wire the cap pack parallel to the ESC wires, with some smaller wires so I can place it somewhere else in the car?
Like seen here ( excuse the amateuristic "paint job " but, you get the idea I hope )

http://i1219.photobucket.com/albums/...40d01cd7e8.jpg

I am thinking about taking the BEC wires back more to the ESC side, and then put some wires parallel to the cap pack ( as short as possible ), is that possible, or does that completly eleminates the use of the cap pack?
And if it is possible, what gauge wire do you guys recommend?

Sorry if these are some stupid questions!

Thanks a lot for all the help, it really means a lot to me!

Ruud

Anyone that can help me with this?

Hi,

yes parallel is rigth. I think 4-5mm^2 (12-10AWG) should be enough but bigger is better.

Parallel is correct.

However, you want to keep the length of the wires to a MINIMUM, as long wires negate the effect of the extra capacitance.

Also, use heavy wires -- maximum currents sourced and sunk by the capacitors can be very high (>100A for short bursts) -- so they need heavy wire to reduce inductance.

Thanks!

Patrick

Ok, thanks guys!
So the best is to solder wires as close to the ESC as possible to have the shortest wire length?
Or would it be better to build a cap bank that has an extra cap or two to reduce the extra length of wire?

Either is acceptable. Whatever is easier in your installation.

Ok, I will take a look at the cost of some good caps.
Thanks a lot for the help!

Sorry to bother you again, but I did some other research on a Dutch forum, and found out that boating guys use cap packs to, like this one:

http://www.tfl-hobby.de/product_info...3-000--f-.html

But does anyone know why they can use thinner wires?
The wires on the pictures don't look like 10 gauge wire, but the ESC's I have seen used are 220 amp ETTI's, Castle's etc?
Not that I do not trust you guys, I deffinetly trust you guys, and appreactiate the tips and advice, but I was just qourius?

Smaller wires still provide benefit, just not as much benefit as larger, more current-capable wire. Like everything, just because someone on the internet got away with it, doesn't mean it's a good idea. Everybody's use is different - one person's version of "beating on it" may be another person's "takin' it easy".

So the effect of the caps is less because the wires cant flow the current given by the caps?
I'll go with 10 gauge, never hurts to have a bigger wire, it is just a bit harder to solder.

I'll try to explain. You want the least amount of resistance between the caps and the ESC. This is why you use low-ESR caps. Shorter and/or larger wires have less resistance. Any resistance will introduce voltage drop, which causes ripple. Very short 20GA wire can have the same resistance as long 10GA wire, but shorter and larger wire is the best.

Smaller wires to the caps can be ok if you use good cells since there is less ripple for the caps to filter to being with.

Weaker cells means more ripple, which means those added caps will have to filter more, which means more current is flowing through the wires, which means more voltage drop on the wires, which results in more ripple.

In short, it's best to use the largest gauge you can without becoming cumbersome and unwieldy. Larger wires may not help, but it certainly won't hurt. Just keep the wires as short as possible and as close to the ESC as possible.

Thanks for the explaination!

Ok, we will go for the bigger wires then, as short a possible.
I use a Gens Ace 5000mah 45C LiPo, a pretty good one, but it never hurts to add a cap pack.
Only the soldering will be a little bit harder to do.
I am thinking to tin both the wires and then lay them against each other, side to side, and then solder them together?

Yes, tinning the wires first is always a must.

Yes, I knew that, but I was thinking, maybe unroll the ESC wire, so that you can make a little hole in it, and put the cap wires in there, but that is gonna be hard and pretty ugly.


Thanks a lot for all the help guys!