You can quite easily make your own... Do you have a soldering iron?
You can quite easily make your own... Do you have a soldering iron?
.NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s
What would be the best setup for extra Caps for 4S to 6S
The ESC has 4 built in 35v - 390uf already.
I have in the past added 4 extra 35v - 470uf caps.
I need to know if this is good, or is there a better way.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
Up to 5000uf additional caps wouldn't hurt ... to be on safe side and all. If you think thats a lot they are 470uf caps after all... but more of smaller caps are better (more efficient) than less of large ones.
A lot of people add (more or less) caps based on ESC though. Just make sure they are new and decent quality caps (Rubycon ZLH or ZL) and not the old/dodgy rubycon stock from Ebay... :P
What kind of ESC are you running?
I run CC 240 Hydra's mostly on 2 & 4S thinking about a 6S setup also.
The ESC has 4 built in 35v - 390uf already.
I have in the past added 4 extra 35v - 470uf caps.
I have not had any problems this way in years.
Is this good enough or is there a better way?????
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
Larry, the 470uf caps would do just fine. Better than nothing should I say. I think 4 or 6 1000uf 35v would be better. That's what I use on most everything unless it's hv then I go up to 50v caps. I have actually picked up speed going from 6 1000uf caps to 10 1000uf caps on one of my saw boats. Not saying more is always better, but it was in this instance. I'm no expert as I learned about caps because of this thread, but this is what's been working for me.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
I like 6+ of the 1000uf as well. Where do you guys get your HV caps? I would love to find some of the RUBYCON 63V 1000u RX 30 like what Etti uses in there high voltage bank, 50V would be fine too. Not having any luck.
Well to be honest I've never checked before and after. I've always just added the cap bank on my builds and my customers builds. The only boat I have that doesn't have an added cap bank is my zelos. But that won't be long before I add one. Likely 4 1000uf per esc I'll add.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Well, castle esc's are known to blow up without extra cap banks... so probably a good idea to go overkill in that area.
Do you know this from experience? I've run several castle escs without cap banks and they never failed. Brushless55 has one in the rigger I sold him. No extra caps. Works just fine. They are very sensitive to water. I epoxy coat every esc I run. Including the castle in his rigger.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Nah, just from the numerous reports and articles I've come across. I believe they have even started putting extra cap banks on their newer esc's.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
belated reply .. lol ..
correct assembly of caps will run the battery and esc a little cooler...
-too many additional caps ( eg 300+% of original ) will punish the battery
-QUALITY rubycon high yield, low esr caps are 16v, 35v or 63v ......... intermediate voltage rates are provided by electrolyte combinations.... ergo avoid the 50v
despite my best attempts at reconfiguring mail filter settings and such.. I fail to rcv notifications from OSE
tag me on FB and I'll pop back over for a chat
https://www.facebook.com/wayne.schutte.56
Wayne Schutte PhdCSE BaSE BaEE. Australian, & damn proud of it YOUTUBE
@ 36" H&M Maritmo twin1512/1800 6S1P 88mph @ 40" drag hydro#1 twin 5692 12S1P .....always for fun @
I was curious at how Travis's boat was running with his setup
I run caps on all my setups even helis
.NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s
drwayne:
Would you say of caps like these which, little did I know before ordering, are Made in China?
https://www.digikey.com/product-deta...1713-ND/756229
They seem like a good brand. This particular new model is some new type of electrolytes. Thought they'd be Made in USA... but Made in China (surprise!) after I received my order of a bunch of them lol.
Btw, any particular way of knowing whether you have too little or too much caps? You say 300% of original would punish the battery...
Here's my new Cap Bank Board for my 8s system. There are 3 types of caps, Low Z large electrolytic, very Low Z polymer electrolytic (smaller cans) and the surface mount MLCC caps, side pic shows them the best. EC5's are directly soldered to facilitate hookups to battery pack (inside set) and ESC (outside set). All components are directly soldered to 0.025" copper strips, providing very low inductance and resistance contributions. Looking forward to putting it to use!
Nice work on the Cap Bank Board.
My only question is the size of your plugs for a 8S system?
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
These are EC5's... I'm looking for a little resistance. An electrical circuit is made of up R, L and C. It's like good chili, need the right balance! But the R is still ridiculously low, about 0.0025 at power and temp, per connector. So that's 0.0025 X 90A X 2 = 0.45V That's the roll off I'm looking for.
Nice.
But not correct.
Under current draw the weaker/lower f caps will inhibit the larger.
EC5 plugs are ok up to around 100A max.
Keep at it.
Wayne Schutte PhdCSE BaSE BaEE. Australian, & damn proud of it YOUTUBE
@ 36" H&M Maritmo twin1512/1800 6S1P 88mph @ 40" drag hydro#1 twin 5692 12S1P .....always for fun @
The reason the separate capacitors are used is based solely on frequency response. At motor fly back frequency, the MLCC ceramic cap is dominant. The polymer cap just helps to extend the bulk capacitor's frequency response. The caps don't get in the way of each other, they react at given frequencies. Don't want to get into an EE battle here, been designing motor drive circuits since the '80's, so very respectfully, I have to rely on my experience.
I am working with a 100A Max circuit. Expecting currents of 88-94A, that's what my target prop size is for.
Keep us updated
Wayne Schutte PhdCSE BaSE BaEE. Australian, & damn proud of it YOUTUBE
@ 36" H&M Maritmo twin1512/1800 6S1P 88mph @ 40" drag hydro#1 twin 5692 12S1P .....always for fun @
Tested the boat with and without the Cap Bank in there. The ESC came in with it showing 142 degrees F. A might warm, but not crazy hot. I put in that Cap Bank I made and the ESC dropped to 112 deg F. I was using more part throttle on that run as I came into the shore. The TVS's read 146 deg F, indicating that they were clamping the spikes well at the 34V level. Those parts can take that temp all day long.
The main Electrolytic caps (aluminum, low ESR) were showing 118 deg F. The liquid polymer caps were showing about 116 and the ceramics were the same temp as the copper conducting rails, 108 deg F. Overall, I think I'll try to get this unto a water cooling plate to see if I can conduct some heat out of the rails and reduce some of the temp on the bulk capacitors.
The test results for me prove that leakage inductance switching spikes are the culprit of part throttle ESC temps rising. The TVS is a very good part to keep it from the ESC, but these parts will get warm. I left the leads long on those parts on purpose, to act as heat sinks. The copper rails are the hottest right under the TVS's.
Next project on my list is to design and build a PCB for this Cap Bank and include a uP that will read the current of the battery system. The throttle signal will enter the uP and will pass thru unfettered if the system is running below the current limit set by some rotary dip switches. If the current goes above, the uP modifies the throttle signal to the ESC by effectively reducing the throttle signal, thus clamping the current draw of the system. Would be great to test upper limit setups and protect the equipment from failure. Couple that with the Swordfish ESC data logger, and you'll see the current limit come in with the reduction of the throttle signal accompanying it. The TVS's need to work, before this scheme will work. I think I have a good foundation to move this heat into a more manageable part of the electrical system and add a very valuable new tool with the current limiter.
Good effort.
Current limiting = power limiting, which is contrary to what this thread is about.
Build a better bank without limitations and get back to us.
Or refer to the specs orovided earlier , and pkay happy.
Regs
W
Wayne Schutte PhdCSE BaSE BaEE. Australian, & damn proud of it YOUTUBE
@ 36" H&M Maritmo twin1512/1800 6S1P 88mph @ 40" drag hydro#1 twin 5692 12S1P .....always for fun @
Yes, current limiting IS power reduction. But this would be an effective tool to get the setup right, so you can take the current limiter off and have confidence what power levels you will be running. I want to use it in tandem with the data logger and fix the set up so it runs on the power budget.
My end goal is to master the use of high voltage packs and make power with higher V, instead of higher A. This reduces the stress of the entire electrical system and helps to prolong battery life, since the current draws will be lower. But these BLDC motors are most unforgiving in trying to reach that goal. I want a tool that will minimize my electrical failures. I see it as a perfect tuning tool to reach no current limited AND no broken parts! I ain't made of money Doc! Thanks for the advise, hang in there with me...
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