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Fishmaxx · 12-04-2006, 10:57 AM

On my Super Class Clod I have aluminum knuckles & axle tubes. It has a under the knuckle batteries. I use 2x diffrent battery packs......1x is a cheap Rat Shack pack I reconfigured, and it works flawlessly. The other is an expensive GP 4300 that has given me nothing but problems. Almost everytime I used it the knuckles and axle tube get very hot.

I think the original problem was my fault cause I didn't test to see if the battery ends could make contact with metal parts. I found it was possible for the battery shift & wiggle its self enough to make metal contact. I insulated the ends seem to help, but it eventually came back. It seemed like the insulation was being worn though, so I rebuilt the packs end so they won't touch no matter how much the shifted.

I know the ends are not touching anything now, but I have noticed the packs label is worn to the metal in some places were it comes into contact with the knuckle & kingpin. Is it possible for this to be shorting out , and cause the heat I described?

Unholy · 12-04-2006, 10:59 AM

Quote:

Originally Posted by Fishmaxx

On my Super Class Clod I have aluminum knuckles & axle tubes. It has a under the knuckle batteries. I use 2x diffrent battery packs......1x is a cheap Rat Shack pack I reconfigured, and it works flawlessly. The other is an expensive GP 4300 that has given me nothing but problems. Almost everytime I used it the knuckles and axle tube get very hot.

I think the original problem was my fault cause I didn't test to see if the battery ends could make contact with metal parts. I found it was possible for the battery shift & wiggle its self enough to make metal contact. I insulated the ends seem to help, but it eventually came back. It seemed like the insulation was being worn though, so I rebuilt the packs end so they won't touch no matter how much the shifted.

I know the ends are not touching anything now, but I have noticed the packs label is worn to the metal in some places were it comes into contact with the knuckle & kingpin. Is it possible for this to be shorting out , and cause the heat I described?

I can't comment as we have not voted to allow under knuckle batteries for 2007 as of yet!!!

Just kidding!

Are you sure you don't have a bad cell?

Fishmaxx · 12-04-2006, 11:05 AM

Unholy, its possible. Its the axle tube that get HOT, and the batteries are slightly warm, so I wouldn't think its transfered heat from the battery.

Unholy · 12-04-2006, 11:08 AM

So the batteries are not as warm as the knuckle? Now that IS weird!
I would think if the heat was caused by a short, the batteries would heat a lot faster than the knuckle! I know the aluminum will absorb the heat pretty fast but I wouldn't think it could get hotter than the cells...

Hmmm. Let me think on this a bit.

Digger · 12-04-2006, 01:53 PM

Aluminum transfers heat much more readily than almost any other metal, which is why it's used for heat sinks and such. While it's most possible that you have a short, I think it's more likely that the aluminum knuckles are acting as a heat sink for the cells. If that's the case, then they would feel hotter than the cells because you are touching the knuckle's exposed aluminum and the cell's insulated label. I would just make sure the cells are fully insulated against shorting out, especially around the positive end of the cell where there's a rim as wide as the rest of the cell that can short out against the rest of the cell's can... Sort of like a soup can, the positive end's rim is also positive, the rest of the can is negative...

Johnson420 · 12-04-2006, 03:28 PM

Quote:

Originally Posted by Fishmaxx

but I have noticed the packs label is worn to the metal in some places were it comes into contact with the knuckle & kingpin.

This sounds like a possible short to me.
Try more insulation protection in that area.

Gimbal · 12-09-2006, 07:36 PM

if the metal wrapper/shield on the main body of the cell touches any other grounded source, including another cell, bad news. You may even want to go so far as to wrap each indiv cell with electrical tape. Or you can get the indiv cell shrink wrap.

slowrockr · 12-09-2006, 08:30 PM

Yea insulate them more from the aluminum. I've had that problem with my touring car before, actually shorted across the carbon fiber chassis

run2jeepn · 12-09-2006, 09:50 PM

Go over all you battery ends and make sure there good. Then dip the batteries in Plastic Dip. That will help protect them...That should fix any short or have on the batteries covers.

JohnRobHolmes · 12-10-2006, 01:14 AM

if you are having problems with the insulation rubbing off, try a bike innertube. Cheap, thick enough, and replaceable if it wears out.

Sounds to me like the tubes are just acting as a heat sink. The aluminum wouldnt heat up from conducting electricity, but the cells would. What are your runtimes? Vent any cells yet?

12-04-2006, 10:57 AM	#1
Fishmaxx I wanna be Dave Join Date: Feb 2004 Location: on a Big Rock Posts: 7,837	Under the knuckle battery short? On my Super Class Clod I have aluminum knuckles & axle tubes. It has a under the knuckle batteries. I use 2x diffrent battery packs......1x is a cheap Rat Shack pack I reconfigured, and it works flawlessly. The other is an expensive GP 4300 that has given me nothing but problems. Almost everytime I used it the knuckles and axle tube get very hot. I think the original problem was my fault cause I didn't test to see if the battery ends could make contact with metal parts. I found it was possible for the battery shift & wiggle its self enough to make metal contact. I insulated the ends seem to help, but it eventually came back. It seemed like the insulation was being worn though, so I rebuilt the packs end so they won't touch no matter how much the shifted. I know the ends are not touching anything now, but I have noticed the packs label is worn to the metal in some places were it comes into contact with the knuckle & kingpin. Is it possible for this to be shorting out , and cause the heat I described?

12-04-2006, 11:05 AM	#3
Fishmaxx I wanna be Dave Join Date: Feb 2004 Location: on a Big Rock Posts: 7,837	Unholy, its possible. Its the axle tube that get HOT, and the batteries are slightly warm, so I wouldn't think its transfered heat from the battery. Last edited by Fishmaxx; 12-04-2006 at 11:08 AM.

12-04-2006, 11:08 AM	#4
Unholy I wanna be Dave Join Date: Mar 2006 Location: One Legend. Posts: 2,134	So the batteries are not as warm as the knuckle? Now that IS weird! I would think if the heat was caused by a short, the batteries would heat a lot faster than the knuckle! I know the aluminum will absorb the heat pretty fast but I wouldn't think it could get hotter than the cells... Hmmm. Let me think on this a bit.

12-04-2006, 01:53 PM	#5
Digger Quarry Creeper Join Date: Aug 2004 Location: Southwestern PA Posts: 259	Aluminum transfers heat much more readily than almost any other metal, which is why it's used for heat sinks and such. While it's most possible that you have a short, I think it's more likely that the aluminum knuckles are acting as a heat sink for the cells. If that's the case, then they would feel hotter than the cells because you are touching the knuckle's exposed aluminum and the cell's insulated label. I would just make sure the cells are fully insulated against shorting out, especially around the positive end of the cell where there's a rim as wide as the rest of the cell that can short out against the rest of the cell's can... Sort of like a soup can, the positive end's rim is also positive, the rest of the can is negative...

12-09-2006, 07:36 PM	#7
Gimbal Rock Crawler Join Date: Mar 2004 Location: Where it's wet Posts: 833	if the metal wrapper/shield on the main body of the cell touches any other grounded source, including another cell, bad news. You may even want to go so far as to wrap each indiv cell with electrical tape. Or you can get the indiv cell shrink wrap.

12-09-2006, 08:30 PM	#8
slowrockr I wanna be Dave Join Date: Oct 2005 Location: Under the 4444 Posts: 2,345	Yea insulate them more from the aluminum. I've had that problem with my touring car before, actually shorted across the carbon fiber chassis

12-09-2006, 09:50 PM	#9
run2jeepn I wanna be Dave Join Date: Sep 2005 Location: USA Posts: 11,196	Go over all you battery ends and make sure there good. Then dip the batteries in Plastic Dip. That will help protect them...That should fix any short or have on the batteries covers.

12-10-2006, 01:14 AM	#10
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	if you are having problems with the insulation rubbing off, try a bike innertube. Cheap, thick enough, and replaceable if it wears out. Sounds to me like the tubes are just acting as a heat sink. The aluminum wouldnt heat up from conducting electricity, but the cells would. What are your runtimes? Vent any cells yet?

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Thread: Under the knuckle battery short?