Minicat Velocity Cat-New

[Boaterguy]

a 30 amp esc is small, it should be upgraded to something around 60.

[martin]

This goes to show that their is a difference between say 25c & 45c on the same set up, The fact that the esc is perfectly happy running a 25c but when you put a 45c it will blow these 30amp esc. I know that for a fact as ive done that on this same motor & esc thats in the Velocity cat & i think Sailr at Minicat Racing has seen enough blown esc returned to him through people using to high c rating. Personaly i use 60amp esc on micro boats on 60c to very good effect as i run a hot set up at 42,000 rpm unloaded turning x632 & x435 Octura. Martin.

[Phaleronic]

Jim refunded some money to compensate for the cracks in the gelcoat, thanks again Jim! Sorry I didn't update this sooner. Jim has been awesome regarding the small crack issue and has been prompt and courteous, a great experience overall.

I'll heed the advice too regarding the batteries.

[sailr]

Our new GII boats have been upgraded to 40A. The 30A never had a problem with the draw from the motor as it only draws about 20-25 amps continuous with spikes to 30. But because the Generation II boats now have a 4 pole, 3200KV motor, we did decide to upgrade to 40A.

We don't have enough of an experience curve yet on the new 40's regarding C ratings. According to the manufacturer, they still recommend no more than 25C. So to err on the side of caution, we're sticking with that. If you have good luck with higher C rated batteries, be sure to let us know.

[Brushless55]

the C rating will not blow the ESC, the C rating is how much a battery CAN discharge, not how much it WILL discharge.
Again use the gas tank metaphor. a gas tank with a large nozzle/ hole can put out more fuel, but the gas won't come out on it's own, but the motor will draw a certain amount of gas out of the tank.

a 30 amp esc is small, it should be upgraded to something around 60.

if the esc is not holding with better lipos, then a bigger esc should possibly be used
maybe just the next size bigger

[sailr]

Read my post just above yours.

[Brushless55]

Read my post just above yours.

already did before I posted

[sailr]

Then you saw that we have gone to a 40A rather than the previous 30A (next size bigger)? Not sure I understand your post then?

[martin]

Can some one please explain to me that a higher c rating will not blow an esc, When these 30amp esc are ok on 25c but will blow going to 45c. If the higher c rating is only the batterys ability to put out more amps why do these 30amp esc blow when on 45c. Its been mentioned that the 30amp esc is not high enough & the next size should be used, But its high enough when using a 25c & dosnt blow. Martin.

[sailr]

While yes, the higher the C rating, the more the pack can deliver, it is also true that the higher the C rating, the more PUNCH they have out the gate! The initial SURGE is much higher. I'm sure those of you who have used a 25C and then put in a 45C in a given boat can see a huge difference in the initial accelleration! Nothing that mysterious! That is one reason that people have been adding more capacitors to their esc's.

[martin]

Sailr i know that & so do you as ive gone through 25c to 45c & now 60c with noticable differences in performance. I would like it explained that a higher c rating wont make any difference to blowing an esc as has been said. Martin.

[sailr]

Yeah, me too. Those who say C rating doesn't matter must know something we don't. A lot of the esc manufacturers have not kept up with the advance in batteries. In fact, in China, they rarely run anything more than 25 or 30C I have been told.

[Rich]

Our new GII boats have been upgraded to 40A. The 30A never had a problem with the draw from the motor as it only draws about 20-25 amps continuous with spikes to 30. But because the Generation II boats now have a 4 pole, 3200KV motor, we did decide to upgrade to 40A.

We don't have enough of an experience curve yet on the new 40's regarding C ratings. According to the manufacturer, they still recommend no more than 25C. So to err on the side of caution, we're sticking with that. If you have good luck with higher C rated batteries, be sure to let us know.

Our new GII boats have been upgraded to 40A. The 30A never had a problem with the draw from the motor as it only draws about 20-25 amps continuous with spikes to 30. But because the Generation II boats now have a 4 pole, 3200KV motor, we did decide to upgrade to 40A.

We don't have enough of an experience curve yet on the new 40's regarding C ratings. According to the manufacturer, they still recommend no more than 25C. So to err on the side of caution, we're sticking with that. If you have good luck with higher C rated batteries, be sure to let us know.

Sailr, as you recall I have purchased a Mini Eco from you sometime ago. I have been running a sky lipo 3000 mAh 30c/ 60c burst. I have had no issues with the esc blowing. The temps stay around 100f. I think the esc it's self doesn't care about the "C" ratings. Its more the caps not being able to cop with voltage changes while running the boat. If you use a lower C rated battery the voltage changes will be larger (= more heat) then if you used a higher C rated battery (= less heat). I add caps to my MeanMachine's esc to cop with this voltage change and it brings down the temps on the caps as well. That being said, the 45c lipos are going to have less of a voltage change, so why are they blowing? What part on the esc is going up in smoke? Also take into consideration that the new 4 pole motors are going to be way more efficient then the 2 pole motors. Repeated on/off throttle also causes extra heat in the caps. Let me throw another brain teaser at you, if I were to use a 25c 2200mAh lipo, that would be 55 amps continuous, which is higher than the 30A, or the 40A for that matter, rating of the two esc's in question. Lets take this a step further, the burst of those lipos is likely to be at or above the 30c mark (depending on the lipo of course), so what is causing the problem? It is for these reasons that I cannot see the "C" rating being the cause for the esc's magic smoke. I hope someone else can give a better insight because this is an interesting discussion.

[Brushless55]

Sailr, as you recall I have purchased a Mini Eco from you sometime ago. I have been running a sky lipo 3000 mAh 30c/ 60c burst. I have had no issues with the esc blowing. The temps stay around 100f. I think the esc it's self doesn't care about the "C" ratings. Its more the caps not being able to cop with voltage changes while running the boat. If you use a lower C rated battery the voltage changes will be larger (= more heat) then if you used a higher C rated battery (= less heat). I add caps to my MeanMachine's esc to cop with this voltage change and it brings down the temps on the caps as well. That being said, the 45c lipos are going to have less of a voltage change, so why are they blowing? What part on the esc is going up in smoke? Also take into consideration that the new 4 pole motors are going to be way more efficient then the 2 pole motors. Repeated on/off throttle also causes extra heat in the caps. Let me throw another brain teaser at you, if I were to use a 25c 2200mAh lipo, that would be 55 amps continuous, which is higher than the 30A, or the 40A for that matter, rating of the two esc's in question. Lets take this a step further, the burst of those lipos is likely to be at or above the 30c mark (depending on the lipo of course), so what is causing the problem? It is for these reasons that I cannot see the "C" rating being the cause for the esc's magic smoke. I hope someone else can give a better insight because this is an interesting discussion.

That's a really good way to put things
having a higher C rating can actually lower cap temps!

[sailr]

It's not the Velocity 30A's that were blowing, it was the Tenshock esc's in the Micro Hydro and Starship. Somehow this got into the wrong thread. You guys can argue all you want. The fact is, and I sell the stuff, that anything over 25C used to blow the 30's!~ OK? I don't care why, I just know it did. Now with the new 40A's in the Micro Hydro, STarship and Mini ECO, it doesn't seem to be such a problem.

Let's put this conversation to bed. Nobody is ever going to agree.