All things being equal - Better ESC - lower temps?

[Racer944]

Hi Everyone;

Newbie questions here. I have a stock Stiletto setup that is running quite hot (batteries and connections mostly). The setup is 1800KV Proboat Motor, 60amp Proboat ESC, running on 4S (2x 2S - 5000mah 40C Gens ace packs).

I want to experiment with props and increase my speed a bit and I was wondering if all things are equal would replacing ESC with one of higher capacity (say a Swordfish 120) keep my temps in check, and allow me a bigger margin of safety to experiment? I am told the motor is easily able to handle more load already.

Also if going to a better ESC is a good idea, is there any advantage to say going to a Swordfish 200A model or would that simply be overkill?

Thanks for the input...

Eric

[driftah]

if you are going to push things further you will need to at minimum upgrade to 5.5mm bullets throughout to help.super hot batteries usually mean you are trying to draw too many amps from them so possibly think about upgrading motor and esc and be very careful with overpropping,someone that has a stiletto may want to chime in and advise you on a good prop choice here.I have heard that a lot of guys are using the grimracer 42x55 mildly detongued and s+b possibly with a backcut as well.

[sanyijr]

My understanding is that if you are pulling more amps through the wiring and connectors that they are rated for, you will have heat build-up that could then lead to higher amp draw from the battery and obviously, less efficiency. I think that is the same thing DRIFTAH is saying.... If motor and ESC are running under good temps, yeah, look backwards towards the power source. Battery "C" looks good for what you are running, so it most likely is a poor connection or under-rated connectors..... Just my thoughts....

[jamespl]

Im running the stock setup but with ec5 connectors and they get warm but what i find strange is that my 7.4v 5800mah 25c batteries run cooler than my 7.4v 5000mah 40c, both sets are turnigy. So how does that work? Just upgraded the motor connections today to 4mm. I was gonna try an x642 prop as the esc is always cool after a run just the packs and connectors get warm!

[sanyijr]

Im running the stock setup but with ec5 connectors and they get warm but what i find strange is that my 7.4v 5800mah 25c batteries run cooler than my 7.4v 5000mah 40c, both sets are turnigy. So how does that work?

I am not sure how the "C" rating is set, but even with higher C ratings, It is not a guarentee that temps won't get warm. Most likely just that the temps would get out of control HOT under the suggested C discharge... Warm I would think is normal in any case. There are many conditions as well that can build increased resistance in the battery. Poor wire connections, poor or bad wires, connectors, long wires, older batteries with higher internal resistance ...... It still amazes me to think that you can discharge these suckers in 5 minutes or even way less time and get warm to touch temps. Imagine pulling these amps from a NICDs. I fried so many of those in the 80s. MMmmmmmm melting plastic!

[jamespl]

When i say warm they arent really hot, you can keep your hands on them and the packs are the same as the connectors. I will have to check them with my infrared heat thingy when i find it. So what are acceptable temps on packs and connectors? also surely if it was pulling too many amps the esc would be hot?
I think ec5 connetors or similar should be common practice to change to on fast electric, i dont know much but i know deans arent great, found that out when they melted on my bj26.

[ilovethis]

sorry tochime in just have a qiick question sanyijr if im running my stock ul-1 motor with a higher esc wont that keep my temps down?

[driftah]

motor will get hot no matter what esc if not loaded properly,the esc will usually fry before a motor will. a bigger esc might help slightly but a lot depends on your prop loading ie size and current demands in the boat..... a bigger esc will just allow the motor to draw more amps if the batts can supply it.heat usually means inadequate connectors or improper prop size or possibly a non free running drivetrain(binding).

[jeepme]

What size battery wires are on the ESC. I had this issue with my MC because my battery wires where 12awg and the esc was 14awg. Once i changed the esc to a seaking 120 ( which has 12awg battery connections ) my connector and battery heat dropped.

[ilovethis]

i just got my ul1 and right now every thing is stock what can i do to go up a notch

[Rumdog]

Go to the Aquacraft RTR section. The UL-1 has it's own forum.
http://forums.offshoreelectrics.com/...-Hydro-Q-amp-A

[ilovethis]

thanks

[oscarel]

if you're pulling too many amps on stock setup you probably have the outdrive too low or too much friction in the outdrive cable. Have you looked at this thread? Darin Jordan here who frequents here I believe help design and test the Stilletto so it should have no issues with heat if set up properly and the lipo's are not bad.

[Racer944]

Hi Oscarel;

Yep, blueprinted the outdrive as Darin suggested and Lipos are new and decent quality. I wil try the outdrive a bit higher although she seems to run at a good attitude on the water. Next step is EC5 connectors all around.

Good disccusion guys, and its not so much about the Stiletto (although that advice is appreciated), but more to educate myself about ESC's and temps...

Eric

[lohring]

Heat is about resistance. The heat generated is proportional to the resistance times the current squared. When you increase the current even a little, the heat generated goes up quickly. The big difference between low cost and more expensive equipment is the internal resistance. This is true of connectors, motors, batteries and ESCs. The stock ESCs that come with ready to run boats often have a higher internal resistance.

Lohring Miller