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-   Brushed/Brushless motors, speed controls, gear drives (https://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/)
-   -   Jeti 18 -3 cutting off at 9.5 volts (https://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/1509597-jeti-18-3-cutting-off-9-5-volts.html)

Bob Payne 02-08-2004 08:40 PM

Jeti 18 -3 cutting off at 9.5 volts
 
I just put an AXI 202826 in a sig lil Rascal with a jeti 18 -3 esc
trouble is when running on a 8cell 1100 ma nimh battery
the esc starts cutting out bad at 9.5 so a full charge lasts about 1 minute.
but if i put in one of my 11 volt lipo's in it then its like a rocket
not to scale when a lil rascal has unlimited vertical and is outa site in a couple seconds.
but the 9.5 cuttoff is nice on that since the lipo pack should not go under 9volts
if i put my 2cell 7.4 lipo in it flys for about 30 seconds then the esc cuts out.
help anyone know how to change the voltage cutoff on this esc??
nothing in the paper that came with it.

Thanks in advance

electricfan 02-09-2004 07:51 PM

RE: Jeti 18 -3 cutting off at 9.5 volts
 
sounds very strange. all my jeti controllers, including the 18-3, have always worked very well. i can think of two problems. 1)the esc is faulty 2)did you check your batteries? they might have something wrong with them

Matt Kirsch 02-10-2004 07:52 AM

RE: Jeti 18 -3 cutting off at 9.5 volts
 
A thread on setting the LVC:

http://www.rcuniverse.com/forum/m_15...tm.htm#1513343

What I've got to ask, though, is how do you know it's cutting out at 9.5 Volts? Measuring the unloaded voltage of the battery after you land is no indiciation of the voltage on the battery in flight. It's far more likely that you've got crap NiMH batteries that can't handle the current demanded from them by the motor, their voltage is dropping severely in flight, and then recovering when the excessive load is removed.

You could very easily be overloading the LiPolys as well, and this is something you really need to be careful about. LiPolys have a very specific C rating for continuous operation. Running a 1200mAh LiPoly with a rating of 6C at 12 Amps will give you about 30 seconds of flying. 6C on a 1200mAh battery is 7.2 Amps, which means the battery can only handle 7.2 Amps on a continuous basis. You can draw more in short bursts once in a while, but trying to do it all the time will damage the battery.

There are many 1100mAh NiMH, many different 11.1V LiPolys, and many different 7.4V LiPolys. Which ones do you have?

Bob Payne 02-10-2004 10:08 PM

RE: Jeti 18 -3 cutting off at 9.5 volts
 
problem solved i just $#it canned the jeti and put a CC25 on it
now i set it for the 2 cell lipo and fly for a long time setting cutoff to 6v
then i break out the 3cell lipo change the cutoff to 9v fly forever.
anybody need a new- used jeti 18-3? $50.00 includes shipping.

Matt Kirsch 02-11-2004 08:11 AM

RE: Jeti 18 -3 cutting off at 9.5 volts
 
Glad to hear you got the problem resolved, even though it was the "sledgehammer solution." :)

BTW, I didn't see that little forsale blurb at the bottom of that post.

(We're not supposed to allow forsale stuff in the regular forums. There's a marketplace for that. It was put there tongue-in-cheek, right? Right? RIGHT!)

Bob Payne 02-11-2004 09:48 AM

RE: Jeti 18 -3 cutting off at 9.5 volts
 

ORIGINAL: Matt Kirsch

Glad to hear you got the problem resolved, even though it was the "sledgehammer solution." :)

BTW, I didn't see that little forsale blurb at the bottom of that post.

(We're not supposed to allow forsale stuff in the regular forums. There's a marketplace for that. It was put there tongue-in-cheek, right? Right? RIGHT!)
yea that was it. :) its not really for sale :i'm gonna put it on my mini telemaster with a pjs-800 should do ok for that because i run 8cell
1700 nimh on it. dont think i'll ever put a lipo in that plane so should be all set.
I had heard jeti was coming out with programmable 10 and 20 amp esc's??
anyone heard that? right now you have to get the 40 and up in the advanced.

Thanks


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