Cap pack?

[SrC]

I do wonder if a parallel cap pack works better if all wirelength from cap's to battery are equal. I've made two designs with this in mind, but i didn't order enough caps to make a third one with all caps in line(and thus different wirelength) to make a real comparison.

I am going to go on a limb and say that the shortest wire must be the Positive lead and this lead should be of the largest AWG if feasible for rapid cap discharge/recharge. I just don't have anything to backup my theory. ?‍ Just my intuitive feeling from my years of soldering leads and caps into circuitry. I am no electrical engineer by any means. But for the most part always successful in designing my wiring layouts.

 

[LibertyMKiii]

I do wonder if a parallel cap pack works better if all wirelength from cap's to battery are equal. I've made two designs with this in mind, but i didn't order enough caps to make a third one with all caps in line(and thus different wirelength) to make a real comparison.

Assuming you have good quality, low resistance wire, I don't think you will find any differences between the two setups. Electricity travels faster than the speed of light.

I have really like this 3d Printed housing so far compared to others I have done over the years.

Sealed up with the cover over the wires:

 

[rotauq]

Assuming you have good quality, low resistance wire, I don't think you will find any differences between the two setups. Electricity travels faster than the speed of light.

I have really like this 3d Printed housing so far compared to others I have done over the years.


Sealed up with the cover over the wires:

Nice to see your 'ridiculous' cap pack in detail LibertyMKiii

My preferred version atm is this one:

8x Jianghai ECR1HGC222MFF751840 caps (2200uF 50V)
My other test version was with equivalent (slightly more expensive) Panasonic EEU-TP1V222, the Jianghai did slightly better in my tests.
all + and - leads are equal length (so no difference between + or - like SrC suggested). Because they are parallel i strived to give them all close to equal resistance. I did use 12AWG though as my 8/10 AWG were out of my stock.

I didn't do any runs lately. Too busy with work, dark early, rain and my XLX2 'died' when i plugged in my new receiver

 

[SrC]

Assuming you have good quality, low resistance wire, I don't think you will find any differences between the two setups. Electricity travels faster than the speed of light.

I have really like this 3d Printed housing so far compared to others I have done over the years.

View attachment 114284
View attachment 114285

Sealed up with the cover over the wires:

View attachment 114286

That is a work of art. Painstaking detail. Form and function.

 

[Edough13]

Ok so wondering if a cap pack would help my issue with my K6s? So the few times I've tried speed runs with the 15t pinion, everything stock(BLX185, 2050kv 4074), ESC goes to limp mode/amp cutoff almost right after reaching full throttle. I've been suggested to give it more space which I've done, nice slow pull and still everytime I'm full throttle it hits amp limit and goes to limp mode. Would a cap pack help stop this? Also have it happen bashing when I hit long stretch and give a full pull will go to limp mode. Thanks for any feedback!

 

[rotauq]

Ok so wondering if a cap pack would help my issue with my K6s? So the few times I've tried speed runs with the 15t pinion, everything stock(BLX185, 2050kv 4074), ESC goes to limp mode/amp cutoff almost right after reaching full throttle. I've been suggested to give it more space which I've done, nice slow pull and still everytime I'm full throttle it hits amp limit and goes to limp mode. Would a cap pack help stop this? Also have it happen bashing when I hit long stretch and give a full pull will go to limp mode. Thanks for any feedback!

Short answer is no. Long answer maybe a little...
If you reach amp or low voltage cutt off, different esc, smaller pinion (less ampdraw, more rpm, potentially more topspeed), better batteries (don't underestimate voltage sag on full load, it demands more amps or triggers lvc)

A cap pack will reduce your voltage ripple (spikes up and down) The lower the voltage the higher the amp draw to deliver the same power. Amp cutoff will not react to a few high spikes of ampdraw. An ESC will allow spikes and short bursts to up 4-5x the rated amps. 950A on the hobbywing Quicrun 08 (which is basically the same as the BLX185). Real crappy batteries will benefit some from the cappack stabilizing the power delivery which could have a positive effect on voltage sag and thus some amp draw reduction. But should be neglected.

 

[LibertyMKiii]

Short answer is no. Long answer maybe a little...
If you reach amp or low voltage cutt off, different esc, smaller pinion (less ampdraw, more rpm, potentially more topspeed), better batteries (don't underestimate voltage sag on full load, it demands more amps or triggers lvc)

A cap pack will reduce your voltage ripple (spikes up and down) The lower the voltage the higher the amp draw to deliver the same power. Amp cutoff will not react to a few high spikes of ampdraw. An ESC will allow spikes and short bursts to up 4-5x the rated amps. 950A on the hobbywing Quicrun 08 (which is basically the same as the BLX185). Real crappy batteries will benefit some from the cappack stabilizing the power delivery which could have a positive effect on voltage sag and thus some amp draw reduction. But should be neglected.

+1 on good batteries.
I'd suspect this is most of your issue.

I took the Stock Kraton v4 electronics to 96mph with a Turnigy Graphene Panther 6s pack 5000mAh

 

[Edough13]

I'm running Hoovo 5200mah 80c 3s packs, not sure these are the worst batteries, not the best but just seems like it hits amp cutoff too easy. Here is some video of it happening, skip to 6 mins in.

 

[Edough13]

Now these are shorter runs after this I was given the advice to give it more room take longer to hit full pull and still same result with longer runs so again just not sure why it is doing this. Also as I mentioned have had it do it while bashing around my 5 acre property as well.

 

[LibertyMKiii]

Now these are shorter runs after this I was given the advice to give it more room take longer to hit full pull and still same result with longer runs so again just not sure why it is doing this. Also as I mentioned have had it do it while bashing around my 5 acre property as well.

It is impossible to give a 100% definitive answer but it is either the ESC acting up or the batteries are too weak.
With the speed pinion in the K6V4 I could get it up to 65mph and the tires were the limiting factor.

Does anyone local have a LiPo you could throw in to see if it behaves better? That would be my best recommendation to attempt to isolate the problem.

Also worth checking the bearings are healthy. Slide the motor back and make sure the truck rolls smooth and easily. Also check the motor bearings...

 

[Edough13]

Bearings in video were all good recently changed to Fast Eddy's, motor bearings all good as well. I'll check with a different set of packs I've got a few different brands Hoovo, Goldbat, Povway. Unfortunately I don't know anyone else around me that bashes or has any different packs to try. I appreciate the feedback and help @LibertyMKiii I know your one of the top speed run guru's on here so I appreciate the input for sure?

 

[Mirkdiggler]

Hello guys.

Do cap packs help with cogging ?

I got a hobao Hyper MT plus 2. It’s cogs horribly. I thought the diffs were jacked at first.

I ended up replacing all diffs with silicone oil. They had grease in all the diffs ?!?!

Anyway. Just trying to figure out this cogging. I have never experienced cogging at this level. Kicking myself because I should have bought the roller.

Thanks.

 

[LibertyMKiii]

Hello guys.

Do cap packs help with cogging ?

I got a hobao Hyper MT plus 2. It’s cogs horribly. I thought the diffs were jacked at first.

I ended up replacing all diffs with silicone oil. They had grease in all the diffs ?!?!

Anyway. Just trying to figure out this cogging. I have never experienced cogging at this level. Kicking myself because I should have bought the roller.

Thanks.

Nope it will not.

Cogging is caused by 3 possible issues.
1. Bad esc
2. Bad motor
3. Aggressive gearing (less likely)

 

[Mirkdiggler]

Nope it will not.

Cogging is caused by 3 possible issues.
1. Bad esc
2. Bad motor
3. Aggressive gearing (less likely)

Upgrade time !!

8s !!

Thank you for the help.

 

[Timson]

Do these cap packs really need such heavy gauge wire? I get that thicker wire = less voltage drop and heat build up, but the connector leads are soldered to a single capacitor lead here - which is what 0.8mm thick!
If the capacitors were all interconnected with heavy gauge wire or via a bus-bar then yes the benefits of heavy wire is obvious. Surely the current flow ability of these packs is limited when assembled this way and the thick wire is just there to make us feel better!

 

[LibertyMKiii]

Do these cap packs really need such heavy gauge wire? I get that thicker wire = less voltage drop and heat build up, but the connector leads are soldered to a single capacitor lead here - which is what 0.8mm thick!
If the capacitors were all interconnected with heavy gauge wire or via a bus-bar then yes the benefits of heavy wire is obvious. Surely the current flow ability of these packs is limited when assembled this way and the thick wire is just there to make us feel better!

Makes em look manly!
Otherwise no it does not matter...