Cap Pack Issue

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Arrma RC's
  1. Limitless
  2. Notorious
After searching google and the forum for the last hour or so I've decided to reach out to the experts. I recently installed a ripple killer 8s cap pack on my limitless running a 1717 motor and monster x 8s esc combo. Gearing was 30T Pinion and stock 34T spool. After the first 3 runs ripple was around .96v or so. After that on the same gearing and lippos my ripple jumped to 3.31v which is higher than it was before I installed the cap pack. My thoughts are I may have fried the pack, but I wasn't sure since that's not to crazy of gearing to my knowledge and only a 112mph pass at about 95% throttle which isn't too crazy compared to a lot of the guys and gals on here. Any ideas of what could be the problem would be greatly appreciated. I attached the 2 castle link logs from the passes I was referencing. I apologize they're a bit blurry.
Thank You,
-Robert

.96v.png


3.31v.png
 
Can you zoom in onto a specific section i.e. one run and save that screenshot? Can't tell anything as it's too much data.
I can already tell you that you need to turn off the low voltage cutoff (the big fat red line).
Might already be the root of your problem, as everything goes haywire at those points.
 
Can you zoom in onto a specific section i.e. one run and save that screenshot? Can't tell anything as it's too much data.
I can already tell you that you need to turn off the low voltage cutoff (the big fat red line).
Might already be the root of your problem, as everything goes haywire at those points.
Thank You for the input. I will def turn off my low voltage cut off I didn't even think to do that. As you can see I'm still very much a noob at the speed run stuff lol. I will try and zoom in on a specific run. I did a specific session option, but it still seems like too much data for one run.
 
Thank You for the input. I will def turn off my low voltage cut off I didn't even think to do that. As you can see I'm still very much a noob at the speed run stuff lol. I will try and zoom in on a specific run. I did a specific session option, but it still seems like too much data for one run.
Go to YouTube and see how to zoom in and isolate different sections of your run on the data log.
 
Thank You for the pointers everyone. Greatly appreciated for a noob like me. I zoomed in on what appeared to be the 2 different sets of data from todays runs keeping everything the same gear and battery wise. I guess on a positive note I did hit a new PR of 117 which is cool.

5.4.22 #2.png


5.4.22 screenshot.png
 
Yes, ripple is too high at almost 3V, that is high even when you pull the trigger slowly.

A tip, look at the throttle graph, you will note that you yank the trigger right at the end instead of keeping a steady squeeze.
The slope is significantly steeper which kills your performance.

You barely stay on full throttle for 1s, you can see on Motor power out it just peaks at 100% before declining.

In other words, lots of room for improvement. Take it as constructive criticism, I never made it past 100mph myself, mainly because I do not have a good stretch of road.
 
^^^ The same here.
I have my Lim geared for a conservative 110-120mph. Yet space where I live limits me to consistent full trigger 98MPH passes.
Need to drop ESC Punch/start power level all the way down. For any dedicated speed running.
Check temps of the cap pack after every pass. One cap hotter than the rest is a sign of a bad cap.
Caps do fail. Been there. I rather build my own cap packs.
CC data logs are known to be erroneous at times. FWIW.
Repeat your passes and observe the logs again.
Like @jkflow stated, 3v+ ripple is too high running 8s voltage. Need to be lower than 10% of total lipo volts. Some say 5% and lower.
You should always get to sustained full power for top end ESC efficiency.
MMX8s should run lower ripple v. without any cap pack.:unsure:
I would run some passes with the Cap pack disconnected and check the data log again. With and without the cap pack.
 
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Pulling a peak of 252a on the one log and dipping down to 25v also makes me suspect you have some rather weak LiPos in there.
What batteries are
Yes, ripple is too high at almost 3V, that is high even when you pull the trigger slowly.

A tip, look at the throttle graph, you will note that you yank the trigger right at the end instead of keeping a steady squeeze.
The slope is significantly steeper which kills your performance.

You barely stay on full throttle for 1s, you can see on Motor power out it just peaks at 100% before declining.

In other words, lots of room for improvement. Take it as constructive criticism, I never made it past 100mph myself, mainly because I do not have a good stretch of road.
Def appreciate all constructive criticism. In regards to full throttle, yes as similar to your situation, I don’t have a ton of space, so throttle control is definitely something I’m working on.
Pulling a peak of 252a on the one log and dipping down to 25v also makes me suspect you have some rather weak LiPos in there.
What batteries are you using?
They aren’t great batteries DXF gold series, but the pack worked 3-5 runs leaving ripple below 1v on the same batteries and gearing. Then all of a sudden it jumped higher than it did before I had the cap pack on which is the issue I can’t figure out. Now that I’ve gotten the speed run bug for sure I’m definitely going to get some SMC, CNHL or Turnigy Panthers perhaps.
 
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Def appreciate all constructive criticism. In regards to full throttle, yes as similar to your situation, I don’t have a ton of space, so throttle control is definitely something I’m working on.

They aren’t great batteries DXF gold series, but the pack worked 3-5 runs leaving ripple below 1v on the same batteries and gearing. Then all of a sudden it jumped higher than it did before I had the cap pack on which is the issue I can’t figure out. Now that I’ve gotten the speed run bug for sure I’m definitely going to get some SMC, CNHL or Turnigy Panthers perhaps.
Sometimes lower quality batteries can get damaged or degrade with heavy use like this. I think the only way to really know if the cap pack is still good would be to charging it up and test it out or put a multi-meter on it and test the capacitance.

Stronger batteries will help quite a bit, but the MMX8s does need help with the extra external capacitors (cap packs).
If you can afford it the XLX2 will run with very minimal ripple (no cap pack needed)

Welcome to the money pit LOL
 
^^^ The same here.
I have my Lim geared for a conservative 110-120mph. Yet space where I live limits me to consistent full trigger 98MPH passes.
Need to drop ESC Punch/start power level all the way down. For any dedicated speed running.
Check temps of the cap pack after every pass. One cap hotter than the rest is a sign of a bad cap.
Caps do fail. Been there. I rather build my own cap packs.
CC data logs are known to be erroneous at times. FWIW.
Repeat your passes and observe the logs again.
Like @jkflow stated, 3v+ ripple is too high running 8s voltage. Need to be lower than 10% of total lipo volts. Some say 5% and lower.
You should always get to sustained full power for top end ESC efficiency.
MMX8s should run lower ripple v. without any cap pack.:unsure:
I would run some passes with the Cap pack disconnected and check the data log again. With and without the cap pack.
Thank you for the input. My punch is at 50% atm i think I’ll make it 75% and see how that is. My ripple before the cap pack was 2.9x volts and with it on for the first 3 passes it was under 1v around .9 or so then it jumped to low 3s. Not sure what’s going on tbh. Something clearly isn’t right though. I did feel the cap pack and it did feel warm but I didn’t check each caps temp.
Sometimes lower quality batteries can get damaged or degrade with heavy use like this. I think the only way to really know if the cap pack is still good would be to charging it up and test it out or put a multi-meter on it and test the capacitance.

Stronger batteries will help quite a bit, but the MMX8s does need help with the extra external capacitors (cap packs).
If you can afford it the XLX2 will run with very minimal ripple (no cap pack needed)

Welcome to the money pit LOL
Yup I definitely see no bottom on this money pit, but the poop eating grin each good pass gives me somehow justifies it in my brain lol.I was thinking about an XLX2,but I heard they caught fire a lot, so as a noob that scared me into MMX8s. I’m sure I’ll be upgrading the setup soon enough with how this addiction is going so far. Definitely excited to get some real lippos now that I’ve made the switch to QS8 connectors.
 
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Speedrun =

Fairly Oddparents Burn GIF

You misunderstood, move your punch to the lowest setting, i.e. zero (or 1).
You do not want any 'punch'.
Understood. Thank you for the advice. I assume it probably is better to master throttle control yourself and have all the power at hand vs what the esc will give you at a given percentage.
 
Update:
Figured out something went bad on the cap pack. I want to thank @phildogg for being nothing but helpful and professional helping a noob like me figure out the problem. He was very prompt and thorough with his responses and sent me a new pack. Definitely recommend Ripple Killer for anyone looking for a top of the line cap pack with top of the line customer support as well.
 
Speedrun =

Fairly Oddparents Burn GIF

You misunderstood, move your punch to the lowest setting, i.e. zero (or 1).
You do not want any 'punch'.
FWIW, on CC ESCs the higher you set the punch control % the more it limits punch. I have mine set to 75% punch currently for speed running. 0% is, counter intuitively, 100% punch. It's inverse to what you would normally expect.
 
FWIW, on CC ESCs the higher you set the punch control % the more it limits punch. I have mine set to 75% punch currently for speed running. 0% is, counter intuitively, 100% punch. It's inverse to what you would normally expect.
Indeed. I haven't messed with any of that since I have been spoiled by PP. I am still trying to find the absolute perfect spot for that as well. Little dot with a sharpie and rubbing alcohol if I need to change it.
 
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