Stupid voltage cutoff

[Daveo]

Ok, I have nearly lost my boat 3 times now because of the voltage cut off on the speed control. Once that thing kicks in the boat is dead. it always seems to go dead in the middle of the lake!!!!!! So is there any way to overide the cutoff with the stock ESC? I would love to be able to get my boat back to shore. The battery still has juice, I know because I have charged them after the ESC thinks they are dead, and they only charge like 50% before they are warm and peaked. I am afraid to run the boat for fear of not getting it back.

[JimClark]

What kind of batteries?

[Steven Vaccaro]

Its a good idea not to drain the cells to far. At some point as the voltage drops, the amperage increases. Thats when the esc can burn up. I would suggest either better cells that keep there voltage up for a longer part of the discharge curve or time your runs and bring it in at a predetermined time.

[Daveo]

ok that is fair, I am currently using trinity GP3300 stick packs I got from the hobby shop. are these good enough?

[Steven Vaccaro]

It depends on how old they are. gp3300's haven't been made for a while. They "may" be at the end of their life cycle.

[Daveo]

But even if I get new batteries, won't the voltage cut off still kick in before the batteries are discharged?

[Steven Vaccaro]

Please dont take this as a knock or insult, since I dont personally know you I dont know your age. Do you know what a voltage curve is? The curve may drop to much but still have lots of capacity. Its what make one battery better than another. Some batteries will start out at 1.20 volts per cell but quickly decrease to 1.05 under a load. The better cells will only drop a bit and slowly decrease over the discharge cycle.

[Fluid]

The voltage cutoff will kick in whenever the pack voltage drops below the set level (can you set that level yourself - what ESC?). If you get good 4300 mAh packs they will take longer to discharge to the cutoff voltage because they have more capacity. Also, new cells will probably hold their voltage longer anyway, so you get longer run time both ways. Your 3300s are probably relatively low grade to begin with, and probably old to boot.

Have you balanced the 3300s recently? If the packs are way out of balance the average pack voltage will drop faster. Put the packs on charge at 0.35 to 0.5 amps until they are done....that may help with your current packs.



.

[ReddyWatts]

There is usually a setting in some controllers for a hard cutoff or one that just slows the boat for low voltage. This will allow you to bring it in when you see it slow down. You could change to a different controller, if that one does not have this option.

Also check all of your battery connections and hot spots in your batteries after a run. A bad connection could cause a premature cutoff.

[ice329]

Since you asking in the SV thread. I would make a guess and say your batteries are the problem. I have not had the cut out, cut anything out yet and I have ran a lot. Get yourself some good IB packs, a decent charger and then I would almost bet your cut off problem will disappear. You should be able to notice a slight loss of power or punch, you know your run is over. Dont over prop the boat and set it up loose. G/L

[ozboater]

all my gp 3300s, 10 packs - 5 runs in the SV get me an average of 4.5 mins at WOT.... more if it s choppy...when it s like that the thing is running waaayyy loose and super dry.... it ll skip 6- 8 ' off smaller chop... mine runs great on nimh, can wait to run it on lipos...

how old are yuor batteries ???

[Daveo]

Steve,

no offense taken, I am 38 and I am an elecrical engineer. I do understand a voltage curve. and I will admit that I have batteries that are old. I think they are a couple years old. Now that being said, here is what I want. I want to run the boat until I see it starting to slow down. Then once it slows down I can bring it into shore. I know, I know poo in one hand and want in the other and see which one fills up first. I am a seasoned RC car guy and that is how I run my cars. I am using the stock ESC and once the boat starts to slow down, I try to get it into shore and it just stops. The steering still works, but the it will not move. Then it never comes back on line unless I power cycle the ESC. Getting the boat out of the lake without swimming is something I have not mastered. So I would love to solve this without plopping down a chunk of change for new batteries. I know I am being childish but I am literaly afraid to run the boat because of this problem.

Thanks for all the help guys!!!

[Bill-SOCAL]

I'm sorry, but it really does appear that your batteries are the issue. Since the rudder servo is working it clearly shows that you are hitting the LVC due to voltage suppression under load. The servo will work down to just under 4 volts but the LVC shuts down well above that.

I really don't see any way you are going to solve this issue without new packs.

[Daveo]

RATS! Oh well, can you point me in the direction of battery recomendations? I have a pit bull X3 charger and a hyperion charger so I can charge just anout anything, but I am on a budget. Having 8 kids is expensive so I don't get to spend too much on rc!

[ice329]

For Nimh try this, go for the 30 dollar 3600 packs...dont get much cheaper then this for GOOD IB 6cell Packs(#IB-36006D2S). I cant tell if there using bars or not but I am sure they will work great. http://www.rcstation.com/index.php?cPath=81_264_278

Or for Lipo's there is one stop, dont look no farther then here http://www.rclipos.com/

[SweetAccord]

Steve,

no offense taken, I am 38 and I am an elecrical engineer. I do understand a voltage curve. and I will admit that I have batteries that are old. I think they are a couple years old. Now that being said, here is what I want. I want to run the boat until I see it starting to slow down. Then once it slows down I can bring it into shore. I know, I know poo in one hand and want in the other and see which one fills up first. I am a seasoned RC car guy and that is how I run my cars. I am using the stock ESC and once the boat starts to slow down, I try to get it into shore and it just stops. The steering still works, but the it will not move. Then it never comes back on line unless I power cycle the ESC. Getting the boat out of the lake without swimming is something I have not mastered. So I would love to solve this without plopping down a chunk of change for new batteries. I know I am being childish but I am literaly afraid to run the boat because of this problem.

Thanks for all the help guys!!!

"poo in one hand"? ugh....sorry I had to laugh when I read that.

[SweetAccord]

1. Maybe you need to use or find something like this if you HAVE TO keep those batteries but this is a band aid not an ideal solution:

http://www3.towerhobbies.com/cgi-bin...?&I=LXLWF1&P=7 or http://www3.towerhobbies.com/cgi-bin...?&I=LXLWF2&P=7

2. Get a cheapo boat to push your dead boat back to shore (kids can play with it too-dual benefit). Even with new batteries you may need this due to other causes for boat retrieval.

3. Ditch the batteries that maybe are NICD since they are old? and go for some good quality NIMH's if you want to keep cost down. Use the NICD's in the cars you have instead till they konk out.

8 Kids wow! I think I see now why you said "poo in one hand" may have been stated. Hehehehe. . . . .

[Daveo]

...
8 Kids wow! I think I see now why you said "poo in one hand" may have been stated. Hehehehe. . . . .

Yeah I am not allowed to use 4 letter words in the house and that kind of spills over into everyday life. It is embarassing but it is a cross that I bear

[ice329]

Note.. someone has ordered from rcstation and said shipping is threw the roof. I have not ordered from there so keep a eye on that.

[Dale Koblitz]

I'de be willing to bet your problem goes away with some good cells. You should get near 5 min. with some good IB 3600 - 4600's and they should stay strong till you notice a slight drop off and would have time to get them back in. Or get some of those elite 4800 lipo's and a 4cell novak lipo cut-off and then you will get maybe 8 to 10 min. and I believe it's a soft cut-off so when it slows down get your butt in or the lipo's will burn through the hull of your boat, JK well maybe. But seriously you just plain need better batterys. But also it never hurts to have a rescue boat for when you get those new batterys and have some real power because then you'll be flippong and rolling. If thats not in the wallet right now hook a tennis ball on the end of a fishing pole line and practice your casting! Good luck!
Dale