Sparks
 

I'm using the gp3300 batteries without being shrinkrapped and I noticed when I picked up the chassis and hit the axcelerator sparks were comming from the batteries and they were extremely hot. I am wondering if this is considered a short and if that could stop the truck from moving. I am able to steer still but once in a while I push on the excelerator and the truck doesn't move. What are the chances if I shrink wrap the batteries so the metal connections are not exposed will stop the sparks and also eliminate the not moving problem. Its like there is no power going to the brushless motor at all, however sometimes it jumps like the power is on for a fraction of a second and stops five six times in a row. Also the receiver, fans and the servos still work when this is going on. Any advice what this problem might be if its not the batteries rubbing against the chassis. :007: :035:

A little frustrated as you can see, please help with any sugestions.

Thanks

Mark

Yes; sparks, hot batts, and no power are all very good signs of shorted batteries. If you don't want to heat-shrink the pack, then at least use some type of insulating material between the pack and any part of the chassis where the batteries contact (and may contact) - like plastic, rubber, etc.

What is probably happening is the short-circuit is momentary, which is why the power comes and goes and would also explain the occasional sparks. Also check the cell casings. The shell of each cell is the same point at the negative lead so if the vibrations abraded a part of that on two or more cells, you are effectively shorting them out.

I do want to shrink wrap them that is what the goal is. I just want to make sure that is what is causing the problems before doing all that work.

Before you do that then, take a piece of cloth or something and put it under and on the sides of the pack as a temporary insulator try it. If there aren't any more sparks, then that's what it was.

Now that makes a lot of sense, thats. Not cloth though, I was thinking about electrical tape around the contacts of the batteries. Also I think electrical tape will be a good insulator.

Any other suggestions or does that seem to be the problem.

Thanks

Mark :027:

It's definately the problem...

One question, if that is the problem and I do shrink wrap the batteries how do I use a discharge tray after the run to even out the cells.

Always drop it to .9 Volts before the next charge.

Thanks.

Yeah, electrical tape can work too. I just said cloth because it will insulate the whole pack (not just the contancts) in case there is something wrong with the plastic sleeve or something.

Well, I suppose you could make some small holes where the contact of the discharge tray go, but that's kinda defeating the purpose of heatshrinking. Add balance connectors? lol j/k.

In lieu of heatshrinking the pack, what about my other idea of adding some insulating material to the chassis itself? I use a rubberized weather stripping I found at Menards. It's about 3/16" thick and doubles as padding for the cells. Just an idea...

Can you be more specific on the rubber insulation, what it is and where to buy it.

Maybe a photo or two.

This thread talks about it. Post #3 has most of the information you are looking for.