Cap pack or not?

[Coopsonthefarm]

I’m running a hobbywing max 6 with a 4292 hobbystar motor. I’m an off road basher. Will a cap pack help my system run cooler? Do I need one? What’s the difference between this and a glitch buster? Thanks for the help.

 

[LibertyMKiii]

Capacitors help minimize oscillations in the voltage. This reduces stress on the esc.
Measurable heat difference on the ESC? Probably not...
Increase the life of the ESC? Maybe, but it has been argued that cost of some cap packs cost nearly half of the ESC.

99% of the time it is used for high speed rigs and bashers seem to operate fine without them. HobbyWing ESCs seem to be quite resilient to the abuse we put them through.

Glitch buster essentially does the same thing but is designed to connect closer to the servo side of the electrical circuit to help supply power on demand when the servo needs it. Most commonly used on higher voltage aftermarket servo units.

 

[Coopsonthefarm]

Capacitors help minimize oscillations in the voltage. This reduces stress on the esc.
Measurable heat difference on the ESC? Probably not...
Increase the life of the ESC? Maybe, but it has been argued that cost of some cap packs cost nearly half of the ESC.

99% of the time it is used for high speed rigs and bashers seem to operate fine without them. HobbyWing ESCs seem to be quite resilient to the abuse we put them through.

Glitch buster essentially does the same thing but is designed to connect closer to the servo side of the electrical circuit to help supply power on demand when the servo needs it. Most commonly used on higher voltage aftermarket servo units.

Thanks so much for that, Super helpful ??

 

[Ari33]

Cap banks are marketed as 'speed improvers', 'punch increasers' and to reduce voltage droop but in reality they have a very minimal effect on all of these things especially if you are using lipis of a reasonable discharge rating.... and any advantage is offset by the weight imo.

They do smooth out voltage ripple and remove spikes... but I doubt you would need THAT amount of capacitance to do that.... Unnecessary ballast?


I fly fpv racing quads where voltage spikes (noise) can be a very real issue and even spikes of up to 30v on 4s have been seen in some cases which is the reason why tend to opt for 35v caps to cover nearly all bases for 4s... as most of us don't have access to a scope.
It can affect the fpv picture and adding some low esr capacitance can help absorb these spikes and improve the fpv analogue picture being transmitted by the VTX. A welcome side effect is that it will likely improve the reliability of all the electronics on the quad by removing high voltage spikes that may be above the specs of some individual electrical components used on the various quad components.
I'm new to the rc car side but I'd say its probably quite likely to be a potential issue worth protecting against here too.
We tend to use high C lipos so none of us have ever experienced any performance boost of the quad itself, we just use them for smoothing.

You'd really need to measure your buggy on an oscilloscope to see if it would benefit from additional capacitance over whats already on the esc.

Too see the transient spikes created by escs that we quad guys are experiencing see-

Hope that helps.

 

[LibertyMKiii]

Cap banks are marketed as 'speed improvers', 'punch increasers' and to reduce voltage droop but in reality they have a very minimal effect on all of these things especially if you are using lipis of a reasonable discharge rating.... and any advantage is offset by the weight imo.

They do smooth out voltage ripple and remove spikes... but I doubt you would need THAT amount of capacitance to do that.... Unnecessary ballast?


I fly fpv racing quads where voltage spikes (noise) can be a very real issue and even spikes of up to 30v on 4s have been seen in some cases which is the reason why tend to opt for 35v caps to cover nearly all bases for 4s... as most of us don't have access to a scope.
It can affect the fpv picture and adding some low esr capacitance can help absorb these spikes and improve the fpv analogue picture being transmitted by the VTX. A welcome side effect is that it will likely improve the reliability of all the electronics on the quad by removing high voltage spikes that may be above the specs of some individual electrical components used on the various quad components.
I'm new to the rc car side but I'd say its probably quite likely to be a potential issue worth protecting against here too.
We tend to use high C lipos so none of us have ever experienced any performance boost of the quad itself, we just use them for smoothing.

You'd really need to measure your buggy on an oscilloscope to see if it would benefit from additional capacitance over whats already on the esc.

Too see the transient spikes created by escs that we quad guys are experiencing see-

Hope that helps.

Could agree more. There is sort of a urban legend around cap packs providing POWER. In reality their ability to provide any sort of amperage is very minimal. On their own they cannot power the esc and motor for 0.5 seconds. Even running small ESC and motor fans they don't last but a few seconds and those motors are pulling 0.5 amps.

 

[SrC]

Capacitors help minimize oscillations in the voltage. This reduces stress on the esc.
Measurable heat difference on the ESC? Probably not...
Increase the life of the ESC? Maybe, but it has been argued that cost of some cap packs cost nearly half of the ESC.

99% of the time it is used for high speed rigs and bashers seem to operate fine without them. HobbyWing ESCs seem to be quite resilient to the abuse we put them through.

Glitch buster essentially does the same thing but is designed to connect closer to the servo side of the electrical circuit to help supply power on demand when the servo needs it. Most commonly used on higher voltage aftermarket servo units.

Glitch buster is just another capacitor. Don't let the fancy name fool you. Its just a capacitor like the rest. Some caps have different ratings. The higher the rating the better it works and the more it will cost....if even needed at all. Some use it as insurance. But, I feel it is just a band-aid for mismatched esc's servos and all your electrics. I have played with them. In the end, there was only one time I feel I "may" have benefited from using a capacitor.( a Glitch Buster) ESC's already come with them built in. If you are pushing your BEC to the limit. A cap can be a band-aid. And incorrect rated caps or those that don't show the rating are suspect from the get go. This is a technical subject that can be hard to understand.
Capacitors designated as an RC accessory are "way" over priced. These caps are basic and simple electronic components that are re-marketed in RC. The markup is astounding. Just search Google. Caps are just dirt cheap electronic gumball components. They literally cost less than a dollar except when marked up for us RC hobby enthusiasts. I can go on and on. I tried to keep this non technical.
I hope this helps.

 

[PowerDubs]

I won't run a cap pack. Snake oil as far as I am concerned. Whatever measurable on a graph drops you see are infinitesimal and in the real world you have something called momentum.

Just like the drag strip, I watched guys bang gears, yet I could take the same car, shift moderately and not be any slower- same car.

 

[jonUF02]

Interesting that the 4s Arrmas have a small cap pack inline with the battery from factory. I'm debating switching to another Hobbywing ESC, but the BLX120 has honestly been fine, and I don't know if I want to sacrifice the cap pack.

 

[SrC]

Interesting that the 4s Arrmas have a small cap pack inline with the battery from factory. I'm debating switching to another Hobbywing ESC, but the BLX120 has honestly been fine, and I don't know if I want to sacrifice the cap pack.

All ESC's have built-in Caps. You may see them or not. But they are there. Some are externally visible. The smaller ESC's have them external because of size constraints. Adding a Cap pack to high drawing powered setups is an advantage sometimes. It will keep the stock caps cooler to an extent. Cap packs are no substitute for bad gearing and higher resulting temps. Cap packs don't make you faster or add more power. And Caps are not snake oil They just make the ESC more efficient and ever so slightly cooler. Less Ripple volts. And ripple volts should always be below 10% of your lipo's voltage. (if you have a Castle ESC that shows ripple logs it becomes more apparent to see this.) Just my spin. Others may have differing thoughts.

 

[jkflow]

Just careful as this entire thread seems to be comparing apples to oranges. These are marketing terms, let me define below.

'Glitch busters' plug into the receiver and smooth out the noise coming from the ESC/BEC. They prevent tiny sags in voltage keeping the receiver from having a brown-out. For modern receivers (Spektrum et al) these are utter snakeoil. If your ESC/BEC can't hold the voltage above 3.5V you have other issues, no spike or servo will create that type of sag without causing other issues.

'Cap packs' for ESC's must be mounted as closely as possible (short wire length) to the battery input on the ESC, again to prevent minor voltage sags (noise).
These do make sense for speed runners to prevent all kind of erratic behavior, a voltage sag can creates a current spike and smoothing these out will prevent ESC destruction due to high current, that is about as un-technically descriptive as I can make it. A 1ms spike is enough to kill any FET out there (more technical..) There are other reasons as well, noise just creates erratic ESC behavior)

All ESC (no exceptions) come with Cap packs that are rated for the ESC. Added cap packs only make sense if you push it into peak/burst performance and prevent the ESC from burning out due to an over-current spike. No 'extra' speed added, you are just more consistent with standard performance which results in higher speed.

In general (and MY opinion !) glitch busters are useless and snake-oil . Check your receiver minimum input voltage to make a judgement call. Your ESC will always be ~ 5.8V minimum on Arrma.
These MIGHT help if you both have a receiver that needs ~5V minimum and a high current servo in conjunction with a receiver that requires high input voltage. Cheaper radios and toy grade stuff might have these issues.

Cap packs, useful for peak applications.

No matter what, a Capacitor has minimal storage capaity and might bridge glitches that are at best less than 1ms long, that is 0.001 seconds. No motor can improve speed as a result, this only helps the electronics.

 

[SrC]

ESC caps should be wired as close to the ESC +/- terminals as possible. (in parallel) Max. of 1 inch from the terminals/exiting wires. No further away from the ESC. Solder into the lipo leads directly. Well ahead of the lipo's. The Cap pack wires must be of same Guage as Lipo leads. A connector if used should also be same as lipo connector. Directly soldered is always best. Use Shortest Cap pack wires as feasibly possible. If you don't follow these basic rules, then your cap pack becomes minimally effective and will overheat/pop. Drop Punch level all the way down for speed pulls. Slow steady TH to max for speed pulls. Cool downs between each pass. Better quality/freshest Caps have the best ESR ratings (cost more) Buying old caps that are dried out perform bad. Best to get caps that are less than a year old and from the same batch production. If building a cap pack from scratch, try to group the best performing caps as bench tested together for best performance. Most probably know this.
Edit:
Rx caps can't hurt your Rx. But as @jkflow stated they are not needed with most quality Rx's. If you think it helps, you probably have other problems. The Term Glitch buster is just a marketting term that has no meaning in what these caps are actually meant to do. Speed run guys use them as back up power for a few seconds of servo power (if that) during a full power loss at speed. (this is not a brown out scenario)

 

[olds97_lss]

In general (and MY opinion !) glitch busters are useless and snake-oil . Check your receiver minimum input voltage to make a judgement call. Your ESC will always be ~ 5.8V minimum on Arrma.
These MIGHT help if you both have a receiver that needs ~5V minimum and a high current servo in conjunction with a receiver that requires high input voltage. Cheaper radios and toy grade stuff might have these issues.

The ones for the receiver are likely more necessary when your running nitro with a 6V NiMH pack and higher current servos. I know if I don't run one with the savox 0231MG servo it causes my receiver to reboot if I turn left/right too fast while applying brake on the other servo. That's with a new fully charged 6V NiMH 2/3A pack.

 

[SrC]

The ones for the receiver are likely more necessary when your running nitro with a 6V NiMH pack and higher current servos. I know if I don't run one with the savox 0231MG servo it causes my receiver to reboot if I turn left/right too fast while applying brake on the other servo. That's with a new fully charged 6V NiMH 2/3A pack.

Rx brownouts/reboots, happen with highly amped servos. A BEC needs a solid and steady 3amp output at the very min. regardless of voltage. Servos that draw too much amps are the problem. Some BEC's can be as high as 12amp/peak. Most High amp drawing Servos are just inefficient by design. IMHO. Not matching them to a high amped BEC is the root cause. Always do your research when selecting a servo. Many don't . They look for the biggest, baddest highest powered $servo$, then they cry trying to get them to work right. Needing a separate BEC or changing out the ESC or trying a "Poop Buster". That's silly $$$ spent, when doing things backwards without careful thought.
BTW Nimpacks in my nitro trucks suck these days. (1600mAh)The current flavors of better servos are best run with small Lipo packs (7.4v) in Nitro RC's. IMHO.

 

[olds97_lss]

BTW Nimpacks in my nitro trucks suck these days. (1600mAh)The current flavors of better servos are best run with small Lipo packs (7.4v) in Nitro RC's. IMHO.

The only one I have issue with is the my nitro with the savox 0231MG in it for steering, it has a hitec 985MG for t/b. The other one has 2 hitec 985MG's in it, one for t/b and steering. That one works fine off a 6V 2/3A NiMH.

 

[kaido]

Stupid question as i don't know how actually does a parallel vs a series connection between a Battery -- CapPack--- Esc works. All i know is CapPack protects esc from current/voltage fluctuations and smooths out power flow from battery.

IS connecting a cap pack in series with the ESC a good idea?

I ordered 6 3900uf FS 50volt series Panasonic capacitors. Is this overkill?

Stupid question as i don't know how actually does a parallel vs a series connection between a Battery -- CapPack--- Esc works. All i know is CapPack protects esc from current/voltage fluctuations and smooths out power flow from battery.

IS connecting a cap pack in series with the ESC a good idea?

I ordered 6 3900uf FS 50volt series Panasonic capacitors. Is this overkill?

When i say "works" i mean effects. Apologies for poor choice of words.

 

[LibertyMKiii]

Stupid question as i don't know how actually does a parallel vs a series connection between a Battery -- CapPack--- Esc works. All i know is CapPack protects esc from current/voltage fluctuations and smooths out power flow from battery.

IS connecting a cap pack in series with the ESC a good idea?

I ordered 6 3900uf FS 50volt series Panasonic capacitors. Is this overkill?

When i say "works" i mean effects. Apologies for poor choice of words.

A group of capacitors suited for the voltage you are running would never hurt. The question is do you have the space for them.
Poorly made they could lead to an electrical short. Other considerations might be weight and airflow for the ESC fan and brushless motor.

I would certainly get a strong grasp on parallel versus series connections before going down this path. There are plenty of videos on YouTube for this subject.

 

[kaido]

A group of capacitors suited for the voltage you are running would never hurt. The question is do you have the space for them.
Poorly made they could lead to an electrical short. Other considerations might be weight and airflow for the ESC fan and brushless motor.

I would certainly get a strong grasp on parallel versus series connections before going down this path. There are plenty of videos on YouTube for this subject.

I definitely have enough place as I verified it by 3d printing a similar size unit(same size as cappack). My only concern is how will it act if i have the pack connected in series vs parallel. Since connecting in series means the cap pack has to charge up before powering the ESC. Will there be a difference in how the rc will accelerate and run continuously, and will it be over stressing the capacitors by leading to premature failure? Speculating that i have a really low to non (1 ohm) internal resistance, if i am thinking right it shouldn't take more than 0.5 sec for the capPack to charge up to maximum. (i am using a venom 35c 3s lipo).

 

[LibertyMKiii]

I definitely have enough place as I verified it by 3d printing a similar size unit(same size as cappack). My only concern is how will it act if i have the pack connected in series vs parallel. Since connecting in series means the cap pack has to charge up before powering the ESC. Will there be a difference in how the rc will accelerate and run continuously, and will it be over stressing the capacitors by leading to premature failure? Speculating that i have a really low to non (1 ohm) internal resistance, if i am thinking right it shouldn't take more than 0.5 sec for the capPack to charge up to maximum. (i am using a venom 35c 3s lipo).

Cap packs are always connected in parallel. This way the power can go direct from the battery to the ESC. Capacitors are rated to handle milli amps. They would get fired very quickly if you wired it up in series.

 

[kaido]

Cap packs are always connected in parallel. This way the power can go direct from the battery to the ESC. Capacitors are rated to handle milli amps. They would get fired very quickly if you wired it up in series.

Haha i was thinking of trying it. Thanks man saved me some work. I am new to electronics and stuff, i am a mechanical engineer i can come up with all kinds of crazy designs and load calculation but when it comes to electricity i am as dumb as a nut.

Cap packs are always connected in parallel. This way the power can go direct from the battery to the ESC. Capacitors are rated to handle milli amps. They would get fired very quickly if you wired it up in series.

Also will i need a cap pack if i am using a 35c rated 3s lipo on a max10 sct hw esc?

 

[LibertyMKiii]

Haha i was thinking of trying it. Thanks man saved me some work. I am new to electronics and stuff, i am a mechanical engineer i can come up with all kinds of crazy designs and load calculation but when it comes to electricity i am as dumb as a nut.

Also will i need a cap pack if i am using a 35c rated 3s lipo on a max10 sct hw esc?

Honestly probably not. You can read through this thread many opinions on it, but for the most part people have determined that HW escs run very well without external cap packs. With that said it wouldn't hurt anything to run a cap pack.