Doing a Brushless Conversion. Advice Please.

[spiftacu1ar]

oh sweet, 47/15 gives me exactly 40.6mph

[spiftacu1ar]

Ok, so I finally finished building my truck, I plugged in my lipos (not fully charged, the cells are at 3.7v each, so at storage charge, not dead either) The first thing I noticed was a large spark as I plugged in the batts. The car still ran, but I am not sure that it is normal. I am using deans ultra connectors, and have the batteries wired in series via a "Y" shaped adaptor I made using 3 deans and 3 wires. (mamba + to battery 1 +, batt 1 - to batt 2 +, batt 2 - to mamba -) All works well when plugged in, as I can drive the car (only went in a small circle in my room to make sure everything works). THe spark was pretty big though, and it kinda scared me, so I wanted to make sure that the spark is normal. Is there something I can do to prevent it?

Also, i noticed that running the vehicle produced a very high pitched noise under acceleration. Also wanted to verify that this is normal.

Lastly, I have a question about mounting lipo's. Is it better to keep them snug and surrounded by only aluminum, or is it better to leave some space around it with foam. I currently have the lipos surrounded with aluminum, with foam in front and behind. The sides are directly up against aluminum. I thought this would help with cooling. I don't know if its the "safe" thing to do with lipos, as I have never used them before, and for me, as a weekend basher, safety comes first

To define snug for those bateries, this is how I have it set up. I have one L bracket on the left side of the batteries. With this in place, there is a little bit of movement with the batts. I then put a 1/32" alum sheet metal on the right side of the batts, which is a slight squeeze to get in. Basically, there is no movement side to side. There is another wall I put in front of the batts, which leaves about an 1/8" of space. I filled this by squeezing a bunch of foam in fornt and behind the batteries. I also bent the 1/32" sheet (to the right of the batts) so that it would also cover the top of the batts. I put a thick piece of foam above the batts, and below this sheet. When I tighten down the velcro straps, the foam is reduced to 1/8" thick, and the batts pretty much don't move in any direction. I will posts pics later, I don't have my camera with me right now.

My basic question is: Should I increase the space to the left of the batts and stuff some foam in there? Or should I leave it as is, which will allow the slum to keep the batts cool.

[Hardstyle]

Originally Posted by spiftacu1ar

Ok, so I finally finished building my truck, I plugged in my lipos (not fully charged, the cells are at 3.7v each, so at storage charge, not dead either) The first thing I noticed was a large spark as I plugged in the batts. The car still ran, but I am not sure that it is normal. I am using deans ultra connectors, and have the batteries wired in series via a "Y" shaped adaptor I made using 3 deans and 3 wires. (mamba + to battery 1 +, batt 1 - to batt 2 +, batt 2 - to mamba -) All works well when plugged in, as I can drive the car (only went in a small circle in my room to make sure everything works). THe spark was pretty big though, and it kinda scared me, so I wanted to make sure that the spark is normal. Is there something I can do to prevent it?

The spark is completely normal when connecting the plugs, it's something to do with the plugs charging up. The bigger the batterys the bigger the spark. It's nothing to worry about, it does wear the plugs a bit but thats all. There is a way to prevent the spark, but it is forbidden to mm/mmm controllers.

Originally Posted by spiftacu1ar

Also, i noticed that running the vehicle produced a very high pitched noise under acceleration. Also wanted to verify that this is normal.

This might be the slipper. You should look that the slipper is tight enough, that it won't slip too much under the acceleration. Not too tight either, so your drivetrain will last longer