What would happen if........
 

What would happen if one were to hook up a motor made for 7 cells to a ESC rated for say 16 cells, and then hooked the ESC up to (2) 6 cell packs run in series? (12 cells total)

Anyone..... Anyone?

RE: What would happen if........
 

As soon as you apply full throttle, the motor will run very fast, for a very short time......poof!

The cell rating of the ESC has nothing to do with how many cells the motor can run on, I run a 7 cell motor on a 30V max (=20 -22 cells) 50Ah ESC.

It's the high voltage that kills the motor.

Should you do this in a boat (= under load) in the water, it's quite possible the boat won't even get on the plane before the motor burns out.

Regards, Jan.

RE: What would happen if........
 

Are you sure it would not burn up the esc first since the extra voltage would have no where to go?

RE: What would happen if........
 

In that respect electricity isn't like water...

The extra voltage will be given to the motor, the ESC doesn't care how much cells you hook up to it (as long as it's within specs) it's the motor at the receiving end that will have to convert the energy into motion, and into heat, as the wires will be too thin, and will heat up to the point of destruction.

But you don't have to take my word for it, just go ahead and try!

Make sure to post the results here.

Regards, Jan.

RE: What would happen if........
 

Jan is right, the esc will be fine, the motor will spin about twice as fast as designed, and put out about twice the power too. then it would overheat and wear quickly. I've done that in the e-maxx, they will last about 1-2 runs.

RE: What would happen if........
 

Well that is why I was asking, because I did this very thing yesterday thinking the motor would be the weak link as well. I checked the motor heat several times, and it never even got warm, however the ESC caught on fire and fused itsself to the hatch cover and servo tray.

The motor is fine, and still works like it always has, but the esc is a total loss. I am still trying to figure out why.

Any ideas?

RE: What would happen if........
 

What motor and what esc? was it?

RE: What would happen if........
 

Stock 550 Motor in Kyosho Wavemaster
RRH SC8 ESC 6-14 cell 85A

I am not sure how to post pics, otherwise I could show you what is left.

So it's not a hypothetical question..
 

Use the "post reply" button instaed of the fast reply.

On the bottom of the window there's a line you click to upload files.

Regards, Jan.

RE: What would happen if........
 

Not sure why the esc should go bad, it seems like it should've handled it no problem. Unless your motor shorted and then the esc went.....

RE: What would happen if........
 

How would you be able to tell if the motor shorted? It still runs fine....

RE: What would happen if........
 

Ok here are a couple pics of the boat when it was running fine on 6 cells, and what is left over of the esc after 12 cells.

RE: What would happen if........
 

If your motor smells like cooked epoxy, you'll know it's at the end of it's useful life. The Kyosho Wavemaster is a little difficult to tweak for top speed. Usually the motor burns out first before the ESC.
Is your 550 motor can & brush water-cooled?

RE: What would happen if........
 

i hate to say but the esc looks like its a little small
looks like it was design for a airplane & under 1100mah cells
i have a esc that wont run a 550 motor but put a 400 on it
& it will run all day long & its a airplane esc

RE: What would happen if........
 

Yup, I agree with you boatman1. It looks like an ESC designed for airplanes!

Size doen't matter
 

In this case, the choice of components is the critical issue.

I have a CTI esc the size of a stamp that will handle 30V (22-24 cells) and 50A continuously without watercooling.

If the wires unsolder themselves, the Fets most have shorted out completely.

Regards, Jan.

RE: Size doen't matter
 

I think I finally have figured it out.

I checked the conenctors, and it looks like some of the plastic melted and shorted things out. So it looks like the next order of business is to upgrade everything to Deans plugs.

The ESC is hard to tell with the scale, but it is made specifically for boats from Rum Runner Hobbies. It is rated for up to 14 cells and 85 amps.

Thanks again for listening to my story. I guess I should have asked first but....... live and learn.

:eek:

Sorry
 

You had to find out the hard way, that the Tamiya connectors are not designed for that kind of loads.

I guess everyone has melted those connectors at some point, I sure have!

Regards, Jan.