MMM Arcing on Lipo Connection - RC-Monster Forums

Shazammer · 04:10 AM

Ok this weekend I got my 2200kv combo all bolted up in my latest project. An E-Revo with Slayer arms, 17mm hubs with 1/8 buggy wheels, and wearing an Associated SC8 body.

On first connecting the battery I get a good pop of an arc coming off the plugs. The esc works great and all but I know it's not supposed to discharge when you plug your batts in. Is it just the way the MMM is? It does seem to be getting less and less the more I've plugged and unplugged it though.

Anyone else have their esc do this?

BrianG · 12.15.2008, 04:33 AM

That's normal. It's just the onboard caps on the ESC charging up. It's more noticeable with higher voltages too.

What's_nitro? · 12.15.2008, 04:41 AM

^ Yeah, it's just the coolness factor of your truck in physical form. The louder the spark, the cooler your truck is!!!

Shazammer · 12.15.2008, 05:29 AM

That's great. I was hoping it wasn't something I needed to worry about.

wallot · 07:06 AM

as long as you wear rubber gloves when using 5S+ lipo you should be ok

btw there is a guide around somewhere how to get rid of the sparks or u can go to mgm-compro.cz website

hoovhartid · 12.15.2008, 07:09 AM

Quote:

Originally Posted by wallot

btw there is a guide around somewhere how to get rid of the sparks or u can go to mgm-compro.cz website

you cant do the "no spark" mod with the MMM. It messes up the calibration at startup.

Just let it spark.

Worst case scenereo, you need to replace your deans after a year or so.

jhautz · 12.15.2008, 09:42 AM

I had one that was like an arc welder when I went to plug it in the first time. After a few attempts of plugging and unplugging the arcing got less and less and eventually went away and the normal capacitor "spark" is all I got. I called CC and they told me that it was some sort of short (my suspision was a dead short across the heat sink on the +/- 6.5mm sockets.) It worked fine after it stopped arcing when I plugged it in. I'm not sure if what you are seeing is the same thing, but what I had happen certainly wasnt "normal" CC replaced it for me. After they got the return unit they called me to ask what was wrong and that the controller was testing fine. I then re-told the repair department what had hapened and they looked closer and told me they could see that there had been a problem. I didn't get into the details as I already had a replacement back from them, installed in my truggy and running fine.

Thomas Porfert · 12.15.2008, 11:31 AM

If you think a 6s spark is bad, you should hear/see the spark that comes from our SHV controllers when they hook it up to 90 volts. Looks like a spark plug firing when you plug it in and it sounds like a gun shot, even in the next room! Love the spark, the spark is your friend.

BrianG · 12.15.2008, 11:35 AM

There's GOTTA be a way to reduce that though without using a potentially harming resistor. I suppose the spark is "cool" and impressive to watch once or twice (or trying to scare those nitro guys

), but it does eat away at the connectors, especially at SHV levels. I don't mind replacing connectors maybe once a season, but replacing them every two runs would be a bit of a PITA.

What's_nitro? · 12.15.2008, 08:30 PM

Quote:

Originally Posted by BrianG

There's GOTTA be a way to reduce that though without using a potentially harming resistor. I suppose the spark is "cool" and impressive to watch once or twice (or trying to scare those nitro guys

), but it does eat away at the connectors, especially at SHV levels. I don't mind replacing connectors maybe once a season, but replacing them every two runs would be a bit of a PITA.

I suppose you COULD use an IGBT or similar semiconductor to switch on the main power for the truck.

One of those big SCRs from a welder would be sweet looking... Come to think of it, I have a box of those so I might try it!

Sammus · 12.15.2008, 08:43 PM

Or just don't use deans. Deans always spark, but since I switched to bullets I dont get sparks at all, you can connect one, and be quick with the otherone and avoid sparking. Deans you have to do both sides in one hit, quickly, making full contact first go, or you get a big spark and oxidise your connectors bad :p

Shazammer · 12.15.2008, 09:39 PM

Quote:

Originally Posted by Sammus

Or just don't use deans. Deans always spark, but since I switched to bullets I dont get sparks at all, you can connect one, and be quick with the otherone and avoid sparking. Deans you have to do both sides in one hit, quickly, making full contact first go, or you get a big spark and oxidise your connectors bad :p

I've gotten good at slipping the deans together trying to minimize the sparks.

I always get the + pole lined up at an angle and get the tip started. Then just put tiny bit of twist on it to get the - pole lined up good. After that just tip the plug together all the way and you are home free.

Sammus · 12.15.2008, 09:43 PM

Yeah, I try and do that too, my success rate isn't great though lol