Why use a Cap Pack on an RC Car? (Capacitor Pack) 

Thanks for the comment Stew- Mac! I certainly appreciate the support by sharing any of the content!

I appreciate that! Thanks for the awesome comment King Stoeck!

Hey LusoiHardware, That is awesome to hear. Thank You for the sub!

Appreciate it Kowlessur Rajiv!

No worries!

Thank you Remko!

Thanks for the sub!

Thanks for the awesome comment Johan!

Thank You for the comment Caribbean Mafia, I'm glad the video can help!

@@RCexplained Your videos are amazing. Thanks for share your knowledge. Will be good enable the auto subtitles in english even better in other languages too like Portuguese. Thanks.

Thanks Mike!

Hey Racing Rivals, thanks a ton for your comment. Really Appreciate it!

@@RCexplained no prob

Thanks for the comment! Glad I could help!

Awesome! Thanks for the comment!

Thanks for the sub! and Comment!

I think servo brown out is one of the main reasons to use a capacitor.

Hey Dex Andrews, thank you for your comment and watching the video!

You're welcome derka5581!

Hey rhouse21, thanks for the comment bud! Yes, you have some good cap pack vids on your channel as well!

@@RCexplained Thanks! You've gotta try to get good info out there somehow. 😊

You can solder directly to the side of the wire close to the ESC

Capacitors really won't help with servo glitches. I don't use any for the receiver, just make sure you have enough current for your servos and all.

Hi Silvio, thanks for your comment, I'm glad you liked and found the video! Your capacitor selection is sufficient for max 12.6v.

Hey Ed, if the ESC came with a cap pack, I would use it. If you were to choose not use it, the life of the ESC would be reduced.

@@RCexplained Thank You

A capack will assist in ripple voltage. If your setup has a high ripple voltage, a cap pack can help.

Yes, no measurable differences there, however your ESC built in capacitors will not be over stressed. This will help increase the reliability of the capacitors in the ESC.

@@RCexplained thanks for your reply, so you don't think I will damage the ESC because I was thinking of trying the 35v 2200uF x7 or the 35v 4700uF x6 or x 7 capacitors, what do you think?

Is it ok if I fit right on connector s going to battery

A cap pack is for the main power going to your motor. This is independent of how your servos are powered.

Ripple voltage does affect the ESC over time, however, if it is managed (kept low) you should expect a long lifespan making it a no issue. The C rating can be calculated from the maximum continuous current you will draw multiplied by 1.3 and then divided by the capacity of a battery pack measured in Ah.

That's a great point. A cap pack will be able to help reduce ripple voltage caused by weak batteries. However a cap pack will never be able to makeup for the voltage drop experienced from weak batteries or an inadequate c rating.

I would replace it if you can't measure Ripple Voltage with the esc.

@@RCexplained ok thank you 😁

Have you tried looking at a diagram? You should be able to pull one up on Google.

2 much man 3000uf enough

Keep it cool

@@RCexplained found solution I gonna run 9.6v nimh instead of 3s on my old school brushed gorgon

A larger capacitor can work and help, however smaller capacitors placed in parallel is best.

A stronger LiPo with a high C rating will help with startup hesitation. Cap packs will not reduce startup hesitation.

RCexplained ok thank u for the knowledge sir.

Thank you for the comment. That is a lot of capacitance. It should be enough!

@@RCexplained thanks. Coz I was just wondering if "overcapping" could damage the batteries or affect the performance of the car.

No. Not enough. You should use twice the voltage caps as the lipo. So minimal 50 or 63v On my 6s setup i already use 50v

Glitch buster has been used for the receiver vs a cap pack being used on the esc. A cap pack used on an ESC is for a very specific and important purpose for the reliability of the ESC. In the distant future I'll have a video on these glitch busters.

Yes, just not enough storage energy to fill massive gaps even on the radio side of any RC.

I'd rather think your bec insufficient for lights AND a high torque servo

@@ChaosRC666 correct

No, caps would not help

Warm the lipo's To 35 Celsius. At least 2 hours before until you use them( inner cells will also need to be warm) . That will drastically lower the internal resistance of the lipo. Otherwise you damage them. Don't think the lipo's already get warm. That is because of the high resistance. It will also give you more punch. Because the lipo transfers the amps way easier. You can make or buy a lipo heater/warmer Niels

Not necessarily. There's a few factors that come in to play. Making sure you can dump the required amount of power certainly will help though!

@@RCexplained it would be an interesting experiment to try. the car audio guys have a similar problem when pushing massive subwoofers, they have to add cap banks or more batteries. You can get some massive caps so I wonder what would be better in an arrma limitless, 1 battery with a super capacitor or 2 batteries in parallel 🤔

I've had to cap my car stereo, the capacitors that would be HUGE for any of these cars. Like the same size for an OK cap, but 2-3 times or more. Higher C batteries, good cables an connectors. The esc also needs to carry the current demanded by the motor without heating too much too fast, or hitting an amp limit by the esc. Aerodynamics, and weight really kill this as a solution to getting instant power to cover voltage or current drops. And, I believe that supercapacitors deliver powe at a more steady rate and wouldn't discharge fast enough to be viable eather. I don't have much experience with them. I've seen batteries with a good bit higher than100c. I'm planning on no lower than100c, the little extra cost has got to be better than putting any kind of limit or strain on the power system at all, it will certainly diminish performance. In speed running, you want to tune the system, not work around bottlenecks. We probably have the most control of the power flow than anything. I take my time, research the options, and think about it all, having a better idea of what is available to work with, rinse and repeat until your just not changing the setup/design anymore, then I feel better about searching price a bit more. I can extend my $ savings time hunting for price as I wait, but I'm not entirely boxed in in my head about price. Said price still being in range. I can't get a thousand dollar esc, but I can get the $200 esc instead of the $120 one because the $120 was lacking somewhere I had to keep working around. The $200 hits your bases correctly, and $300 I was drooling over isn't missed So much. Or, just wait a bit longer for the $300 one. Same with batteries and the rest of the power system, not a place to cut corners, and a real pain to chase the problems that come with it.then your left with gearing, aerodynamics, bearings, weight, ect, power systems can make your vehicle, break your vehicle or completely make it go up in smoke. I'm currently entertaining the idea of a boat or jetboard esc, they run some high extended current pulls. Heatsink it well with high speed fans, could work. Gonna experiment. It's just my little opinion. Been fabricating and repairing much in a half century, and my opinions come from experience. That doesn't mean it's right, just where I got my opinions from. And I do ramble on in the comments section late at night, I'm working on it. IF I'm correct, then, may it help others in the quest for performance. Or, I'll shut up, eventually...

Ok, after many minutes of scouring the web for information I have come to the conclusion that I won't be running the supercapacitors either. Gotta hook too many in series to get the required voltage, and for current draw, but the power delivered is just not justified as a solution for me. That, and to hook them up to be even marginally effective will decrease service life. I still believe that high discharge batteries, proper wiring and connectors to handle more than my actual draw, and an esc that can let the current demanded by the esc is the best way to deal with voltage sags and current drops for instant and sustained purposes. If the motor isn't the onl serious draw on the power system, there will be a limit to performance best case, and a melted puddle where your car used to be. Both RC vehicles, and full-size alike. Although, if you haven't seen a good car fire, it's one heck of an experience!

Hey Mike. It's unfortunate your car was crashed and needed a rebuild. It's going to be tough to say what is happening within many of the components on your car. You can verify the battery is ok with a resistance check to ensure it has not changed since the crash. If the battery pack changes shape, resistance can increase. The second battery can be a close comparison as well as long as both pack were capable of 100mph prior to the crash. Another quick area to check is driveline resistance. You will want to confirm that the resistance within the driveline has not increased over time. I would not suspect the ESC to be an issue, (nor a capacitor issue) however it would be best to review a datalog if possible to see what is going on with the entire system as a whole. Another thing you can do if possible is swap to an equivalent ESC to see if there is a difference.

@@RCexplained hi. Ok. Thank u for your reply. Both battery packs did take it to 100 mph So strange for it to be happening with both packs. I cant see how both would have same issue. I checked shafts and they are straight. It pulls awesome tons of power gets up to now its new peak of just 80 mph and doesn't pull to higher speed.

Hello Isogen, I'm not experienced with their use in drones. I would expect the reason for their use to be more for FPV guys who are trying to filter out higher frequencies to avoid interference or RF issues in the FPV feed. Especially if the power system is operating off of the same battery the FPV gear is. In this case, LC filters are reducing noise that affects video quality. Instead of an LC filter, one could just run a separate battery for the video feed with improved results. Much different purpose vs a cap bank to protect the ESC.

Hi Thanks for the comment! www.radiocontrolinfo.com/ first tab is the Shop

I'm not sure what you mean here: "I think batteries can accelerate battery failure because they need to send power to super capacitors and motors."

@@RCexplainedI'm sorry, it's a translator.I mean, if the capacitor is depleted while driving, the battery will have to send electricity to the motor and capacitor at the same time, so I think the voltage drop will get worse.

The capacitors and the battery pack will both be at the same voltage. If the capacitors have been depleted, that would also mean that the battery would be depleted.

@@RCexplained Thank you for your answer. Can I think that the more capacitors the better? Except for spark when plugging in.

@@RCexplained Sorry, that was a stupid question.

Are you going to be making speed runs or pushing the system very hard? Stock configuration as the manufacture lists in the manual would be sufficienct for bashing the car around.

@@RCexplained i pushing the system very hard and wont protect the esc grom verbal volteg, but i dont know wiche cap pack i need, can yyou help me?

You can use a standard cap pack that has a minimum of 800μF.

@@RCexplained TNX!!

Do you have a data log of the run? What is getting hot?

@@RCexplained I don’t have a data log but the motor gets crazy 160+ definitely, and the esc gets really hot in pretty normal weather gets hot even on the street and ect

A cap pack will not help the motor getting hot. Reducing load or moving to a larger motor and ESC will help.

@@RCexplained will it help esc heat?, I can’t really go any bigger on the motor , and with the esc I can’t find a 8th scale esc small enough

What is the make and model that you bought?

It's a virhuck "cracker" rock crawler.

@@RCexplained It's the same as this video here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ix5zBKDUmXk.html

@@radunit4805 I'm not familiar with the crawler. I'd have to see a picture of what you are looking at. I would expect there to be a battery. I would suggest asking the individual who is taking it apart in that video.

@@RCexplained it really is a capacitor, I unsoldered it from the board and saw a print saying "Lithium Capacitor 3.7v"

I'm no expert but from my understanding, the cap packs only reduce the amount of ripple voltage which can damage the esc hence increased reliability of the esc . It does not protect batteries, it doesn't affect performance (No speed increase, no acceleration boost).

I agree with you. From what I got it prolongs the life of an esc and should definitely be applied.

You kind of answered your own question. You are correct you will get a more consistent speed run but at the end of the run will not see a higher top speed.

Hi nts 323, the easiest way to determine the best voltage spec is to look at the specifications on the capacitors of your ESC. If your ESC hides these specifications, a 35v capacitor bank would work for 6s and lower. 50v for 8s and under.

@@RCexplained thank you👍👍

Welcome to RC Racing Everett

I think in general you got it. Cap Packs help the capacitors so that the grouping of capacitors can protect the FETs from seeing too much ripple voltage, otherwise the FETs could turn to smoke before the caps. Capacitors reduce the ripple voltage, however they won't be able to make up for any voltage sag caused by weak low C rated batteries.

@@RCexplained Ah ok. Thanks for responding. Love the videos man! Keep up the good work.

Sweet I need one of those!

If you are experiencing significant Ripple Voltage, they are necessary, otherwise the esc is at risk for failure.