What would you do? - RC-Monster Forums

jayjay283 · 01.13.2009, 04:08 AM

So long as hes not wearing a dress

sikeston34m · 08:34 AM

A Reverse Polarity Situation?

Did you know Deans Connectors are actually marked?

I highlighted the markings with a sharpy for this picture.

I bought a RC Boat from Ebay one time. It has a pair of Titans in it and the EVX ESC. Just to try it out, I got a pair of my 5000mah Lipos that I had been using with Monster Trucks.

I'm not sure if the ESC was turned on or not, but there was a HUGE spark when I plugged it up.

The Wires got VERY hot and one of my Lipos let go. All of this happened in a few milliseconds. I didn't have time to unplug it before this happened even though my hands were still on the plugs.

This took out the ESC and one of my Lipos.

After some checking, I figured out the guy I got it from had "upgraded" to Deans.

He installed them reverse polarity on the ESC, AND on his batteries. So it worked for him.

He would not make good on it. I filed a dispute with paypal about it, thinking I would show them my "proof".

The guy left me negative feedback accusing me of lieing about the entire thing. Then Paypal ruled in his favor and closed the dispute without even contacting me for more information.

If you get something used, it pays to double check everything.

lincpimp · 01.13.2009, 11:19 AM

Quote:

Originally Posted by sikeston34m

If you get something used, it pays to double check everything.

This needs to go in the "tips" thread!

I have seen all kinds of horrible wiring and other abortions of nature. I buy alot of stuff used (I am cheap) and always give everything a thorough once over before I use it. I do buy alot of used lipos off RcGroups (plane guys take good care of their stuff) and never buy without pics.

kulangflow · 01.13.2009, 12:00 PM

Quote:

Originally Posted by sikeston34m

A Reverse Polarity Situation?
After some checking, I figured out the guy I got it from had "upgraded" to Deans.

He installed them reverse polarity on the ESC, AND on his batteries. So it worked for him. If you get something used, it pays to double check everything.

I had that exact same thing happen to me. Fried a good lipo and ESC because the previous owner installed his Deans backwards and I didn't double check it first. Shame on both of us!

pb4ugo · 01.13.2009, 12:13 PM

Quote:

Originally Posted by kulangflow

I had that exact same thing happen to me. Fried a good lipo and ESC because the previous owner installed his Deans backwards and I didn't double check it first. Shame on both of us!

I'm wondering (and asked him) if he didn't change connectors. I'm almost certain it was reversed. I sent them with Deans on them that were correct. The first pack was run without issues, then boom the second one causes all the trouble.

sikeston34m · 01.13.2009, 06:53 PM

Quote:

Originally Posted by kulangflow

I had that exact same thing happen to me. Fried a good lipo and ESC because the previous owner installed his Deans backwards and I didn't double check it first. Shame on both of us!

It does put on quite a show doesn't it?

The absolute Maximum Burst Capacity of Lipos must be way up there when you dead short them. LOL

What type of ESC fried on you?

kulangflow · 01.13.2009, 07:16 PM

Quote:

Originally Posted by sikeston34m

It does put on quite a show doesn't it? What type of ESC fried on you?

It was quite a show, but not quite as impressive as when I accidentally dead-shorted a 10s a123 pack!

I can't remember the name of the ESC. It's been a while. It was a brushed ESC, so I guess I really wasn't out much. I was much more annoyed by the lipo loss.

JERRY2KONE · **Thats cool. -** 01.13.2009, 07:22 PM

Quote:

Originally Posted by kulangflow

It was quite a show, but not quite as impressive as when I accidentally dead-shorted a 10s a123 pack!

I can't remember the name of the ESC. It's been a while. It was a brushed ESC, so I guess I really wasn't out much. I was much more annoyed by the lipo loss.

That is too bad, but it is very cool that you can come here to share the experience with everyone here. It may give just one person a good enough reason to be careful and double check their own stuff in order to avoid this type of catastrophy. We all learn from mistakes, so why not someone elses mistake???

sikeston34m · 01.13.2009, 07:25 PM

Quote:

Originally Posted by kulangflow

It was quite a show, but not quite as impressive as when I accidentally dead-shorted a 10s a123 pack!

I can't remember the name of the ESC. It's been a while. It was a brushed ESC, so I guess I really wasn't out much. I was much more annoyed by the lipo loss.

Since we're talking about "Dead short" shows, this reminds me of an incident at work.

I was changing out an SB350 Connector on one of the forklift batteries.

They are 1000ah 36 volt, Lead Acid type, and weigh about 2850lbs each.

To get the lugs out of this type of connector, there are springs that you have to press down with a flat screw driver, then the lugs will slide out the rear.

Well, while I was pressing, something slipped, the connector turned and that screw driver was suddenly jammed in there shorting the terminals.

It snapped that screw driver in a spray of pretty sparkly thingies.

I think the correct word is "abated". LOL

JERRY2KONE · **Stories. -** 01.13.2009, 07:50 PM

Back when I was in the Navy stationed in Hawaii I had a co-worker do something similar with an 18" screw driver. All I saw was a bright flash of light, and the only thing left of the screwdriver was a piece of the handle about the size of a common egg. The rest of it had desintigrated/vaporized. he was checking for voltage and did not feel like climbing down from the ladder in order to get his muiltimeter. What an ass. Scared the bejesus out of everyone around, and he fell off of the 20' ladder that he was standing on. Some people actually have accidents, and some are just stupid.