Matched Cell Problems.
01-16-2007, 05:19 AM
#106
Originally Posted by Mosc_007
WRONG, In the last 20 years ONLY the IB4200's have EVER exploded Violently.
I have seen ABUSED cells before that have melted and split open but neven Violently exploded.
I am talking about NiCD or NiMH cells. Lithiom have caught on fire and Lead Acid batteries do Explode violently at times. But Never have NiCD or NiMH cells expolded violently untill the IB4200 came along. And I suspcect it was the matching that weakened the cells allowing them to go short circuit when fully charged. They must have a VERY Thin insulation layer between the +ve and -ve layers which allows them to breakdown. They must be thinner in order to get more chemical in the cell to give more capacity.
Charles
I have seen ABUSED cells before that have melted and split open but neven Violently exploded.
I am talking about NiCD or NiMH cells. Lithiom have caught on fire and Lead Acid batteries do Explode violently at times. But Never have NiCD or NiMH cells expolded violently untill the IB4200 came along. And I suspcect it was the matching that weakened the cells allowing them to go short circuit when fully charged. They must have a VERY Thin insulation layer between the +ve and -ve layers which allows them to breakdown. They must be thinner in order to get more chemical in the cell to give more capacity.
Charles
As I said before, no consideration for the physical and mechanical aspects of RC cars and the impact to the cells...
01-16-2007, 05:22 AM
#107
Originally Posted by vr01
What about the ESC's? They are designed to have virtually no resistance which dumps the power out the cells at an astronomical rate. Surely if an ESC or motor shorts it will put huge stress on the cells, more so than the charging / matching process...Chris
Not to mention the wiring and PCB tracks will NEVER be able to handle that current they rate them at.
You put a short on your motor then run your ESC. You will have a completly destroyed ESC in a matter of seconds. Unless of course the ESC has an over temperature shutdown. Which will shutdown in seconds if not less.
Charles
01-16-2007, 05:23 AM
#108
Originally Posted by vr01
Well we will agree to disagree.
As I said before, no consideration for the physical and mechanical aspects of RC cars and the impact to the cells...
As I said before, no consideration for the physical and mechanical aspects of RC cars and the impact to the cells...
Charles
01-16-2007, 05:24 AM
#109
Originally Posted by Mosc_007
WRONG, In the last 20 years ONLY the IB4200's have EVER exploded Violently.
I have seen ABUSED cells before that have melted and split open but neven Violently exploded.
But Never have NiCD or NiMH cells expolded violently untill the IB4200 came along. And I suspcect it was the matching that weakened the cells allowing them to go short circuit when fully charged. They must have a VERY Thin insulation layer between the +ve and -ve layers which allows them to breakdown. They must be thinner in order to get more chemical in the cell to give more capacity.
Charles
I have seen ABUSED cells before that have melted and split open but neven Violently exploded.
But Never have NiCD or NiMH cells expolded violently untill the IB4200 came along. And I suspcect it was the matching that weakened the cells allowing them to go short circuit when fully charged. They must have a VERY Thin insulation layer between the +ve and -ve layers which allows them to breakdown. They must be thinner in order to get more chemical in the cell to give more capacity.
Charles
Chill out man, i have seen SCE's , SCRs, Sanyo 2000s, GP3300 "explode".. all of them, at races, twice at home..
What gives ??
Even a search on the rctech forum will give you various stories of all makes of cells blowing up..
It is also very easy to make any cell explode just by setting the delta peak wrong..
01-16-2007, 05:26 AM
#110
Originally Posted by Patriiick
Well, your mileage may vary.
Chill out man, i have seen SCE's , SCRs, Sanyo 2000s, GP3300 "explode".. all of them, at races, twice at home..
What gives ??
Even a search on the rctech forum will give you various stories of all makes of cells blowing up..
It is also very easy to make any cell explode just by setting the delta peak wrong..
Chill out man, i have seen SCE's , SCRs, Sanyo 2000s, GP3300 "explode".. all of them, at races, twice at home..
What gives ??
Even a search on the rctech forum will give you various stories of all makes of cells blowing up..
It is also very easy to make any cell explode just by setting the delta peak wrong..
On older cells setting the delta peak wrong used to just melt the cell and it spills its guts. I have not heard of one going off like a shotgun.
Charles
01-16-2007, 05:29 AM
#111
Originally Posted by Mosc_007
No I am not retired. I am 46 Years old.
If you dont believe my test results then do what I do. I never believe what people tell me.
If you dont believe my test results then do what I do. I never believe what people tell me.
By the way Charles You do seem to be very selective when you quote or say you have read from other posts
01-16-2007, 05:29 AM
#112
Originally Posted by Mosc_007
WRONG, In the last 20 years ONLY the IB4200's have EVER exploded Violently.
01-16-2007, 05:30 AM
#113
Originally Posted by Mosc_007
It sounds like you are a person that believes the current rating that ESC manufacturers put on their controllers.
Their rated current is for about 1 mS. The true average current rating is less than 1/6th of what they say. The rated current is at a junction temperature of 25 Degrees C. And since ESC's have almost no heatsink capacity the Junction temperature will reach the 150 Degree C limit in an extreamly short time. You would need a Heat sink a thousand times larger with fans to run them at that rated current.
You put a short on your motor then run your ESC. You will have a completly destroyed ESC in a matter of seconds. Unless of course the ESC has an over temperature shutdown. Which will shutdown in seconds if not less.
You put a short on your motor then run your ESC. You will have a completly destroyed ESC in a matter of seconds. Unless of course the ESC has an over temperature shutdown. Which will shutdown in seconds if not less.
01-16-2007, 05:32 AM
#114
Originally Posted by Patriiick
It is also very easy to make any cell explode just by setting the delta peak wrong..
http://www.rctech.net/forum/showthre...xplode+battery
PS. That looks like a non-IB4200
01-16-2007, 05:32 AM
#115
they go off exactly like a shotgun
01-16-2007, 05:33 AM
#116
Originally Posted by addicted
This has sumed things up for me with this thread..
By the way Charles You do seem to be very selective when you quote or say you have read from other posts
By the way Charles You do seem to be very selective when you quote or say you have read from other posts
You will notice I keep saying comparing the RC3600HV's to IB4200's at a 10 Amp discharge.....
I am absolutly certain that at a 20 Amp discharge the IB4200's will have a higher average voltage. The Manufactures data sheet says it will. But at 10 amps it's the other way round.
Charles
01-16-2007, 05:34 AM
#117
Originally Posted by mangoman
I know for a fact that a guy i race with had a non IB4200 explode (i think it was a GP3300). Luckily for him he was not near the battery at the time.
Charles
01-16-2007, 05:36 AM
#118
Originally Posted by vr01
Hardly, merely trying to illustrate a point.
So from what you are saying the cells are always protected? (Which I doubt...) What you have also illustrated is the tremendous heat soak that exists particularly for mod TC which no doubt also stresses the cells.
So from what you are saying the cells are always protected? (Which I doubt...) What you have also illustrated is the tremendous heat soak that exists particularly for mod TC which no doubt also stresses the cells.
CVharles
01-16-2007, 05:36 AM
#119
Originally Posted by Mosc_007
It is a fact that batteries used in RC cars get abused electricaly and mechanicaly. If these IB4200's cant handle that sort of abuse then maybe they should not used in RC applications.
Charles
Charles
01-16-2007, 05:42 AM
#120
Originally Posted by vr01
Might as well not race then as you won't find any cells that can handle that sort of abuse with 100% reliability.
5 Years ago the reliability was VERY high. But back then the chinese were not making racing cells.
It sounds like the IB4200's are probably less than %50 reliable. When the matcher said he has had Thousands of IB4200's die during matching it would be nice to know how many were ok. And out of the ones that were ok how many of them lasted say 6 months...
Charles