12s esc from kershaw

[Deluge]

Sweet! That boat should haul ass.

 

[krashkrieg]

looks just like mine. I have the 250 amp 8s of this esc. At the other end you can see the anti-spark set up as well.I also have a Pair of 280 amp 16s marine esc's that I'm using in a boat build that is a 60 inch Catamaran.

Is that the lid to the catamaran or a really thin boat?...Those ESC's look HUGE!

 

[twissted]

This is mine it is a Fightercat 250 amp 8s esc. My next step is a 10 hp motor! Batts are 4s lipos rated at 130c runnung is series.

 

[twissted]

Yes!

They are big and the boat is big, so it works!

Is that the lid to the catamaran or a really thin boat?...Those ESC's look HUGE!

 

[twissted]

I hope the esc doesn't get hit!

I ran 2 screws through the rear brace and into the heat sink.

I think I would move the servo upright and move the esc next to it. Clean and simple!

 

[BoukeG]

Here is my test result:

 

[Deluge]

Nice! Runs good.

 

[BoukeG]

Thanks, yes it runs great. To be honest, at times it was quite scary. I've never been able to get it to full throttle, so there is more than enough power.

It didn't caught fire, so I guess that is a good thing too .

I'll try to go to a larger open area this week, but the weather isn't great at the moment...

 

[Guest]

Here is my test result:

That shreds the grass.

Runs great.

 

[BoukeG]

Thanks! I just compared my other movie clip running the 1600KV on 6S. On that movie I was almost always at full throttle. Now on this clip I hardly ever hit full throttle - let alone getting to full speed. More than enough potential!

 

[bigfol]

Thanks! I just compared my other movie clip running the 1600KV on 6S. On that movie I was almost always at full throttle. Now on this clip I hardly ever hit full throttle - let alone getting to full speed. More than enough potential!

Looking good bouke, now its time to gear up and really get it moving.......

I'm waiting on a 18t pinion to come in, going to run it with a 46t spur and if the temps stay in check will drop it down to the 41t spur, should give it some legs.

 

[ninjagaiden]

Here is my test result:

That's really nice. Liking your lighting kit too!

What's the beeping mean. You can hear it at the end of the vid. Is it an LVC cutoff?

N

 

[twissted]

I wonder why is didn't come with a fan cover?

 

[BoukeG]

The beeping is my lipo warning device. It was set to 3.2V. Which I think should be safe enough. However, I've found they can beep rather fast. It measures each individual cell. At times it goes under 3.2V for just a second and the warning kicks of. I usually just wait a few seconds and if it is stops, I just continue running. If it keeps beeping, I'll drive it over and check them.

In the end of the movie clip, cell 1 of a lipo was destroyed. It was 0 volt, so permanently damaged. I keep thinking: was this just a bad copy, did I stressed it too much, are these lipos capable of supplying the power I need, do I need to stop immediately after the first beebs (which might also happen when just starting driving, having a cold lipo), do these lipo's need a burn in the first couple of times?

I was happy I got the warning device though, since the LVC cutoff didn't went off. Which is logical. When I stopped, all other cells were on 3,74V. 11*3,74V = 41,14V. 41.14V / 12 = 3,43V. The LVC stops at 3,2V. So I guess you just need a lipo warning device running 12S.

 

[BoukeG]

I was just doing some calculations, correct me if I'm wrong.

Max volt lipo (1 cell) = 4,22V

Nominal volt lipo (1 cell) = 3,7V

@ max volt 12S = 4,22V * 12 = 50,64V

@ max volt 12S = 4,7 * 12 = 44,4V

The motor is 1000kV. 12.000W max. Pulling 240A @ 50 Volts which = 12.000W. So the ESC at 280A @ 50 Volts is capable of supplying the power pulled by the motor. Also, then voltage drops, 12.000W / 44,4V = 270A, so ESC is still powerful enough to power this motor (12kW = 16 HP by the way - just amazing).

Next up my lipos. They are 65~130C @ 5000mAh. So that is 325A. @ 50 volts it should be able to supply 16.250W. Well over the required power by the ESC.

So if my calculations are correct, the lipos should have no issue at all to run this system... I even calculated using the normal discharge (65C), and not the peak (130C). I hope I just had a faulty cell.

 

[bigfol]

I have had faulty cells on new lipo's before, its a bit hit and miss with some brands, I always top up my lipos with a charge before running them, I've been told they like to be warmed up before use....are they nano-tech's from hobbyking?

 

[killajb]

I'm of the frame of mind that if your batteries dip down to 3.2 volts per cell, the load on your system is enough to reach the threshold of reliable battery operation. I think the lowest I've seen voltage drop is 3.4v/cell, once things hit the 3.2 mark it's shut down time and I have to persisit driving it past that point (which I don't).

 

[BoukeG]

are they nano-tech's from hobbyking?

Yes they are, you've had the same problem?

Okay, so it seems these lipos are not able to do the task. Now what would help them? Shorter wires? Cap bank?

I think I'll try some gen ace lipos. I've been reading they are good. I'll save these for other occasions...

 

[bigfol]

Yes they are, you've had the same problem?Okay, so it seems these lipos are not able to do the task. Now what would help them? Shorter wires? Cap bank?

I think I'll try some gen ace lipos. I've been reading they are good. I'll save these for other occasions...

Yes I had a pair that puffed really badly after a few runs, but the IR was still only 2 to 3 ohms in each cell......go figure, but my new set are holding up really well, its a bit hit and miss with these lipo's, I have also heard good things about Gen Ace lipos, yet to try them though.......If you can afford them hyperion are your best bet.

Shorter wires and a cap bank is only going to benefit the esc.....

 

[BoukeG]

Shorter wires and a cap bank is only going to benefit the esc.....

Hmm, okay, I thought so... Anyway, looking at those Hyperion lipos I see them go up to 45C.