Cap Pack - two types - one for ripple one for boost?

[LibertyMKiii]

Interesting. In my above referenced build, I tested the cap packs with the same method that Jason did in his FloPack video. I let them charge for awhile with electronics armed and then pulled the battery while the ESC was still powered up. Like you, I experienced nothing after disconnecting the LiPo. It would not even briefly power the servo, ESC, or fans. Are Jason’s units simply that much better, or am I missing something here? I was surprised that literally nothing happened.
And again, I’m not expecting something over the top. Just the ability for a quality cap pack to handle ripple and voltage sag to some limited extent.

It is possible he is using super capacitors that have significantly more capacity, but the last time I checked they were only rated for low voltage. To utilize them you would have to put many of them in series to handle higher voltage. Not quite sure what he is doing but it seems to work.

I'd love to see another video to confirm it not provided by the person trying to sell the product.

 

[jkflow]

Haven't seen the video but if you disconnect any load to the BEC i.e. unplug receiver and fan you should be able to power it for a couple seconds. ESC itself probably doesn't draw a lot of current.
At any rate, it truly has no impact on any performance, no matter how much snake oil is being added. There are super caps out there, but they have a very low C rate and can't handle running a large load unless we go back to trailer sized caps (1/8 scale trailers).

 

[eyeopenher]

I know this is not the same, but this is my experience with capacitors…. I tattoo for a living. When I first started, no tattoo machine ran caps…. Then one day they were a thing… the results, no spark, a smoother, cooler, better running machine… more consistent and a clean slap of the armature bar to coil….

Without the caps, we would get a very dirty spark, with a harsh running machine… chattery with a hiccup every now and then… also the contact points would get more carbon on them and have to be filed more often… machine would run hot and hard… you could see the difference int the needle marks…

Now if you added 2 capacitors to your machine, it would smooth it out more and make the machine a ripper… it would multiply the reciprocations per minute… they had machine with 3 caps on them with a toggle switch to run 1,2 or 3 caps… thing ran like a chainsaw with 3 caps working. Hahaha

So I am surprised this doesn’t help with speed or boost… but my tattoo machines are very different then animal then an RC rig… I plug into AC power witch is converted to DC… Then rheostat for fine tuning… we do have PWM in our power supply now a days, but that is not everyone’s cup of tea…

 

[jkflow]

Completely different animal, your tattoo machines don't run on 3 phase and do not have to deal with turning power on/off at high frequencies. They are fairly simple devices that had a very basic AC/DC conversion with a resistor inline to regulate the power/speed. Basically, your DC looked like 2 sine waves going from 0 to positive. With caps, it's significantly smoother. No real comparison to the issues with ESCs.
I'm sure it helped you, in your specific application.

 

[yaboyhamz]

had 12v ripple on my xlx2 and it straiht up unsoldered the wires from the board. Castle replaced it and I got a cap pack soldered on new one. Haven't seen over 2v ripple now

 

[gotnitro]

had 12v ripple on my xlx2 and it straiht up unsoldered the wires from the board. Castle replaced it and I got a cap pack soldered on new one. Haven't seen over 2v ripple now

Not every electrical component is made the same. There are usually 2 reasons you get ripple. 1, a possible problem coming in from the battery (lacking) and 2, possible internal component failure. Not melt down magic smoke failure, just lack of quality in the component.

Could the caps on the stock ESC board be bad or not properly performing? Sure! In that case, caps would help with ripple if you are into checking a computer after every run.

For me, I don’t give a squat why an ESC smokes. All I want is a new one or a better one, so if one smokes, I buy another. Some are in this hobby on budgets. IMO not a hobby to be into on a budget lol.

 

[eyeopenher]

Completely different animal, your tattoo machines don't run on 3 phase and do not have to deal with turning power on/off at high frequencies. They are fairly simple devices that had a very basic AC/DC conversion with a resistor inline to regulate the power/speed. Basically, your DC looked like 2 sine waves going from 0 to positive. With caps, it's significantly smoother. No real comparison to the issues with ESCs.
I'm sure it helped you, in your specific application.

Yeah, I am sorry. I didn’t know if it would help at all. I knew it wasn’t rc related, but was hoping something in brain helped. Hahaha
A tattoo machine is just an old style doorbell… that’s it. Secret is out. Haha

 

[Just a hobby]

Not every electrical component is made the same. There are usually 2 reasons you get ripple. 1, a possible problem coming in from the battery (lacking) and 2, possible internal component failure. Not melt down magic smoke failure, just lack of quality in the component.

Could the caps on the stock ESC board be bad or not properly performing? Sure! In that case, caps would help with ripple if you are into checking a computer after every run.

For me, I don’t give a squat why an ESC smokes. All I want is a new one or a better one, so if one smokes, I buy another. Some are in this hobby on budgets. IMO not a hobby to be into on a budget lol.

Being disabled and unable to work. I've been on a budget with the hobby for 10 years now. I'm still having fun. Just takes longer on ordering expensive parts.
No big deal.

 

[gotnitro]

Being disabled and unable to work. I've been on a budget with the hobby for 10 years now. I'm still having fun. Just takes longer on ordering expensive parts.
No big deal.

Yea no disrespect to the peeps on a budget at all, was just saying. I mean, I know of many other things to do that would keep my hip fat

 

[Just a hobby]

After seeing some uf numbers, I can assume I went to high with this capacitor? I have 4 put together for a 6s setup in my limitless.

 

[Dan B.]

At any rate, it truly has no impact on any performance, no matter how much snake oil is being added. There are super caps out there, but they have a very low C rate and can't handle running a large load unless we go back to trailer sized caps (1/8 scale trailers).

Not sure how you can say this when so many very experienced people here have posted before/after Castle logs resulting in way less ripple, especially with the MMX8S.

 

[jkflow]

Not sure how you can say this when so many very experienced people here have posted before/after Castle logs resulting in way less ripple, especially with the MMX8S.

Not arguing the ripple reduction, my comment was with respect of a 'power boost'. Cap packs can't do that but agreed, wasn't clear in that post.

After seeing some uf numbers, I can assume I went to high with this capacitor? I have 4 put together for a 6s setup in my limitless.

It's a fickle game, you want high uF but very low resistance. Now, resistance and capacity p[lay nice together, you add caps in parallel and capacity adds up while the resistance is an inverse function and is half (with 2 equal caps). Therefore, it's always preferential (for cap packs) to have multiple caps in parallel.
You will never have better results with a single cap.

 

[Dan B.]

Not arguing the ripple reduction, my comment was with respect of a 'power boost'. Cap packs can't do that but agreed, wasn't clear in that post.

Gotcha, and agreed. The laws of physics do not support claims of any kind of “power boost”. From what I’ve seen on other peoples logs they don’t even do much for voltage sag, which seems to only really be remedied by the use of better LiPo’s.

 

[SrC]

Right, but just because HobbyWing ESC’s don’t provide data logging doesn’t mean that ripple doesn’t exist. I installed Phil‘s 8s Ripple Killers on my last speed build. An 8s capable cap-pack on a Max 6. I have no way of quantifying its benefits, or lack of, but I’m hoping to overcome the ESC’s cut off due to amp load at WOT as it nears 100mph. From the research I’ve done, the arguments support a theoretical advantage. I don’t expect “boost” from the cap pack, or some sort of magic bullet, just the ability of the cap pack to somewhat smooth ripple enough to avoid ESC cut off under high loads.
In regard to your earlier post, the general consensus from speed runners pulling (and understanding!) Castle logs is that the MMX8S most definitely benefits from a good cap pack. Many do say that the XLX2 either doesn’t need one at all, or at least needs it to much less of a degree.
And just to be clear, I am not one of those who yet understand the nuances of reading the Castle logs or have anywhere near the experience of those whose results I’m citing.

Interesting. In my above referenced build, I tested the cap packs with the same method that Jason did in his FloPack video. I let them charge for awhile with electronics armed and then pulled the battery while the ESC was still powered up. Like you, I experienced nothing after disconnecting the LiPo. It would not even briefly power the servo, ESC, or fans. Are Jason’s units simply that much better, or am I missing something here? I was surprised that literally nothing happened.
And again, I’m not expecting something over the top. Just the ability for a quality cap pack to handle ripple and voltage sag to some limited extent.

A cap pack cannot hurt you. It just needs to be a good adequate one, and installed correctly to limit high Ripple volts, if any.
I didn't know the MMX8s was that less efficient with Ripple, than the XLX2.
Many have experimented with Super capacitors. They are rather large, and costly.
And caps don't last forever FWIW. They get very hot doing their job. Heat cycling them over and over is what bricks them over time. They usually pop their lids when they fail. Normal. Sometimes not. Check their temps. Some caps will get hotter than the rest. A sign of an out of spec. cap.

 

[RC-Dude]

So how long do capacitors last? Is there a time after which it makes sense to get a new transmitter or throw receivers away after a set number of years? Or throw 10 year old BECs away even if they work perfectly? Mostly thinking about aeroplane transmitters and receivers here.

 

[jkflow]

A better way of thinking about cap packs is to what they actually do, they are filtering out the noise, nothing more nothing less.
With that mindset it will put it into better perspective.

SuperCaps are acting more like a battery but can't handle the load unless you put a bunch in parallel, they are usually in the 2-5C range i.e. for the ~ 50C you would need ~ 20 in parallel. In addition, if you charge them up with your lipo you are defeating the purpose, plus you still need a cap pack to filter the dangerous noise.
Obviously, you could charge the super caps externally, that would add energy to the setup, but at that point it's still better to run a 2nd lipo in parallel. In short, it's just making something simple very complicated.

So how long do capacitors last? Is there a time after which it makes sense to get a new transmitter or throw receivers away after a set number of years? Or throw 10 year old BECs away even if they work perfectly? Mostly thinking about aeroplane transmitters and receivers here.

Life is typically listed on the datasheet but depends heavily on the design and actual use of the system. If exposed to heat they go a lot faster, if designed for low use or within spec it's based on operating hours (datasheet) and if circuits are over designed it might just be the normal deterioration of materials (think 100's of years). Keep in mind that electronics still work nowadays on Voyager and other older equipment.

20-50 years in car like designs, consumer electronics 5-10 years or an overheated cap pack due to high ripple maybe 5 minutes.

 

[#arrmaalltheway]

After recent purchase of a MMX8s and their "less than stellar" capacitor set, please sell me on why I'll require an external cap pack for speed running.

Does anyone have a back-to-back runs with/without an additional cap pack? Looking for improvement in performance-top end MPH along with any obvious heat/failure or voltage sag "apples to apples" comparison.

Thanks

I was doing speed runs in a parking lot so I was on the throttle quicker then I should. The space made me. With the caps the car would shut down and I would have to reset it. Now I installed them in my vendetta and my limitless to handle the extra draw.

 

[SP3SWJ]

HI all,

I see a lot of discussion, but no any masurment done to proove something.

Fistr I show some measurment done on 2S powered car and small and big capacitor test, we can see how VOLTAGE SPIKE is reduced. Video is old amd made generally for own use and local friends to show.

This picture show measurement done usien osciloscope connected to power line paralell to supply. We can see that in this case we shourd use 25V capacitors for 8,4 powered car 2S.

Measurement was made on DYNO on real RC car.

Few yars later I made simmilar video but for XLX2 8S powered car.

When I run with no cap pack I obserwve RIPPLE in castle log about 1,6V then I build 16 x 1000uV 50V Panasonic Low ESR and on ripple i observe reduction to about 0.81V for 560A @ 27V

Measuremnt with osciloscope confirm that voltage spike reduce 2x lower with propper mounted capacitor.

My capacitor have resistance 0,00155 ohm. = 1,55 miliohm

We need remember that cable 8AWG lenght for about 20 cm add 0,3 miliohm.

And this is measurement of my ripple from log

And this is some play with measurement.

If someone wants to check if the capacitors give something, it's very simple.
We do the run,
we take the Logs.
We add the capacitors.
we do the same run
we downlad Logs
We have comparative results
... and we can compare - SIMPLE.



End of my booring bla bla


If someone wat to discuss why we have this SPIKE and why is danger for ESC and BEC - this is material for another tech discussion.

 

[gotnitro]

HI all,

I see a lot of discussion, but no any masurment done to proove something.

Fistr I show some measurment done on 2S powered car and small and big capacitor test, we can see how VOLTAGE SPIKE is reduced. Video is old amd made generally for own use and local friends to show.

View attachment 320244

This picture show measurement done usien osciloscope connected to power line paralell to supply. We can see that in this case we shourd use 25V capacitors for 8,4 powered car 2S.

Measurement was made on DYNO on real RC car.

View attachment 320245

View attachment 320246


Few yars later I made simmilar video but for XLX2 8S powered car.

When I run with no cap pack I obserwve RIPPLE in castle log about 1,6V then I build 16 x 1000uV 50V Panasonic Low ESR and on ripple i observe reduction to about 0.81V for 560A @ 27V

Measuremnt with osciloscope confirm that voltage spike reduce 2x lower with propper mounted capacitor.

My capacitor have resistance 0,00155 ohm. = 1,55 miliohm

View attachment 320249

We need remember that cable 8AWG lenght for about 20 cm add 0,3 miliohm.

View attachment 320250

And this is measurement of my ripple from log

View attachment 320251

And this is some play with measurement.

If someone wants to check if the capacitors give something, it's very simple.
We do the run,
we take the Logs.
We add the capacitors.
we do the same run
we downlad Logs
We have comparative results
... and we can compare - SIMPLE.



End of my booring bla bla


If someone wat to discuss why we have this SPIKE and why is danger for ESC and BEC - this is material for another tech discussion.

Nice write up! No one is questioning ripple. I think everyone and their grandma knows caps reduce ripple.

The funniest part is, when people read ripple currents from castles prog, they STILL get out there and beat up their RC creating you guessed it, more ripple. For me, why bother looking. Waste of time. If the ESC smokes, chances are everyone will be getting a new one. Nothing is better than raw power directly from a quality battery on 8ga with short runs.

 

[SP3SWJ]

... If the ESC smokes, chances are everyone will be getting a new one. ...

Good point of view ;-) maybe XLX3 will be better ;-)


Overpowering give a lot of fun and big chances to blow up ;-)