Cap banks - the pre-emptive answer

[ray schrauwen]

It has been a thought of mine for some time that why mosty Suppo esc's burn up is most likely due to faulty caps they buy in massive quantities not caring if they are way out of spec or just not made right at all. I mean, the fets on Suppos are a discontinued fet in USA that was shipped in container loads to China like many other obsoulete electronic components.

A while back I grabbed a near new HK SS100 esc and the cap wires nearly fell off from inside the caps?? I replaced the caps with blue 1000uF 35V-130* Rubycon RX30's right onto the board. It works very well now.

I remember Etti used to use the Suppo base board BUT, they used the blue Rubycon's instead.... wonder why.

+1
ditto CC240LV 3+ years back... use to burn cap leads ... 4S 1515/1Y - pop .. changed to upmarket caps.. 6S1527/1.5Y
around then decided to design own esc.... never looked back
W

THis esc is still running well even when I use it to test iffy or bad motors on bench.

Cool... $20 esc....

[golfito]

There seems to be a lot I should read, subscribed! .Thanks Wayne.

[CraigP]

Yes, there's 150deg C caps too with high ripple current. They are NOT cheap! If you buy your own, remember there are 2 ripple specs, 60Hz and 100KHz. You want to look at the 100KHz number. Good caps aren't small in size, they need some mass to handle the heat. Some of these little dinky caps they are installing in these ESC's are a joke!

It's not necessary to replace, putting good ones in parallel will bolster them up. I buy my caps from Mouser, spent a lot of time researching specs.. If anyone is interested in some part numbers, just let me know...

[dasboata]

Yes, there's 150deg C caps too with high ripple current. They are NOT cheap! If you buy your own, remember there are 2 ripple specs, 60Hz and 100KHz. You want to look at the 100KHz number. Good caps aren't small in size, they need some mass to handle the heat. Some of these little dinky caps they are installing in these ESC's are a joke!

It's not necessary to replace, putting good ones in parallel will bolster them up. I buy my caps from Mouser, spent a lot of time researching specs.. If anyone is interested in some part numbers, just let me know...

you have a PM Craig

[gearhd48]

My question here after reading this is what mathematic calculation is needed to figure out how much Uf you need for what amp draw & voltage to get the optimal capacitance?

[gearhd48]

Here is some great video info on youtube calculating your needs. Capacitors (1 of 11) in Series, Calculating Voltage, Charge and Total Capacitance look it up.

[drwayne]

My question here after reading this is what mathematic calculation is needed to figure out how much Uf you need for what amp draw & voltage to get the optimal capacitance?

Hi
After reading all this. you would be aware that cable length/inductance.. battery quality.. plug resistance .. motor efficiency etc etc etc are a mixed bag..
There is no single complicated? calculation to provide an answer for the best capacitance array suited any setup.
One needs consider multiple factors which could be potentially different across differing situations, and consider your own setup when reading this thread.

For eg
Im currently running pair [ HIFEI X300 to 5692/780Kv ] from 12S1P65c5000 source ( Au class limit )
The amp loading here is impressive, driving 1665 wheels.. the initial launch draw(250A) is harsh as I launch hard , and at high rpm the voltage spikes are abhorrent..thus the cap bank caters to both the initial voltage sag, and upper rpm frequency buffering.

Thus I use 10x 470uf 63v low esr 103c rubycon.. fast reply, adequate voltage support, and fast recharge.
5x 1000uf do not offer fast recharge, and consecutive draw attempts may see a degradation.

Sorry..no magic calculation ... just a direction for you to take towards a solution

regs

[gearhd48]

I thank you for your time to reply this. As you said this will be leading me into a new direction for knowledge! I'll be heading to OZ to ask the wizard, Oh wait you are in the land of OZ! I've got a mate in Queensland....Well I'm of to learn more and do some testing! LOL Tim

[dmitry100]

Any of you guys know what this cap bank is and what is the difference between this and regular caps?

https://www.offshoreelectrics.com/pr...prod=etti-e081

[drwayne]

Hi
Just revisited this after countless years .. still holds !
W

[ray schrauwen]

In general yes it does. So far with the new Castle ESC's they are saying a cap bank is NOT required.

[TRUCKPULL]

In general yes it does. So far with the new Castle ESC's they are saying a cap bank is NOT required.

It Not just that it is NOT required,
If used it can damage the new type of circuits that stop excessive heat.

I am pulling 400A on 8S with a Castle XLX2 - Ripple is 0.61V
Why would I want an extra cap bank.

I do use Cap Banks on all my older ESC's.

Larry

[Steven Vaccaro]

It Not just that it is NOT required,
If used it can damage the new type of circuits that stop excessive heat.

I am pulling 400A on 8S with a Castle XLX2 - Ripple is 0.61V
Why would I want an extra cap bank.

I do use Cap Banks on all my older ESC's.

Larry

Larry who said it would hurt them? the guys I know locally using the xlx2 also used cap banks with no problems.

[TRUCKPULL]

Steven
This came from Tyler Garrard it the thread (has a new ESC been born)

In all my data logs, my ripple voltage using the X8S
on 6s-300A- 2.03V Max at this ripple level I don't believe extra caps are required.

XLX2 -8s-361A- 0.61V Max ripple.

Larry

[Steven Vaccaro]

Steven
This came from Tyler Garrard it the thread (has a new ESC been born)

In all my data logs, my ripple voltage using the X8S
on 6s-300A- 2.03V Max at this ripple level I don't believe extra caps are required.

XLX2 -8s-361A- 0.61V Max ripple.

Larry

Thanks