Puffed lipo while connecting to esc

[RcDriver]

I have a Senton and my 180 esc was burnt so I got a 185 esc as a replacement.

All my lipo batteries have hxt 4mm connector (I believe) and I have been using the deans connector since my old 180 esc had the deans connectors on it. I had no problems with them so far.

I ordered this connector from ebay (http://www.ebay.com/itm/HXT-4MM-Bul...583a7ad&pid=100005&rk=1&rkt=6&sd=381877318596) and connected it to my lipo and plugged into the new 185 esc.

As soon as I plugged them in (2 x 3S Turnigy 4000mah lipo), the smoke came out of the connectors and puffed the lipos. I immediately removed the connectors but they were already melted.

I am fairly new to rc car and would like to know what I have done wrong. Did I buy the wrong connector?

Should I have bought this instead? (http://www.ebay.com/itm/DIRECT-CONN...18596?hash=item58e9a973c4:g:ziMAAOSw4GVYSKzn(

The lipo batteries are puffed so I don't want to use them anymore (too risky I guess) but what about the new 185 esc? Is it dead? =(

Please advise.

 

[WoodiE]

@RcDriver consider yourself lucky to even be posting this. LiPo fires can be severe.

To keep this short as possible, yes you ordered the wrong adapter and you should have picked this up just by looking at the second photo you've attached. Black goes with black and red with red. Your second photo shows red with black and black with red.

This is just one reason why I don't encourage the use of adapters. Make it easy on yourself and in this case MUCH safer and just buy a some XT90 connectors they are really cheap and easy to do.

Everyone, new and old to the hobby, needs to understand what they are dealing with when messing around with LiPo's. Many of us just drool over the power LiPo gives us over other types of batteries and while that is great and all - LiPo batteries can be dangerous if not handled with care. Do we need to be reminded of the exploding Samsung Note 7?

Going back to your questions - yes the puffed LiPo's are toast and not worth risking. Consider this the cost of learning. Get new batteries, either with the XT90 pre-installed or install them yourself (skip the adapter). Then test the ESC, you've got a 50/50 chance it's dead as well.

 

[RcDriver]

Thank you for the comments, Woodie. I should have paid more attention. It was a good lesson for me. Hope the new esc survived. =(

 

[Kauaiguy]

Thank you for the comments, Woodie. I should have paid more attention. It was a good lesson for me. Hope the new esc survived. =(

I would guess your ESC is toast, if bad enough to puff your batteries. There is no reverse polarity protection other than the caps on the ESC and they would only take a short for a split second.

Might also take out the Rx and servo?

 

[Unusual RC]

To top this off: soldering different connectors to a lipo battery has the equal risk of short circuiting the battery during the process.
You need to cut-off the wrong connector, strip the wires. When they are exposed, even the slightest contact between the two leads means mayhem!

Handle with extreme care. And make sure you take decent precautions to cover off (electrically isolate) the opposite pole when you work on the other.

As @WoodiE states changing connectors is not difficult, but if done wrong it can have the same devastating results!

 

[WoodiE]

I would guess your ESC is toast, if bad enough to puff your batteries. There is no reverse polarity protection other than the caps on the ESC and they would only take a short for a split second.

Might also take out the Rx and servo?

Yes the ESC is very likely toast as well, but only way to test is to plug in the battery and see. There is a chance the receiver could have been fried as well since shorts like this can possibly take out all sorts of things, servo's included. That said there is a good chance it fried the ESC and stopped there.

@RcDriver since you're in the market for a new LiPo battery now might I suggest checking out SMC Racing for new batteries. They make great LiPo's and will pre-install XT90 connectors for you which will match your newly bought (likely) BLX 185. Again no adapters needed.

 

[Dustin Mustangs]

To top this off: soldering different connectors to a lipo battery has the equal risk of short circuiting the battery during the process.
You need to cut-off the wrong connector, strip the wires. When they are exposed, even the slightest contact between the two leads means mayhem!

Handle with extreme care. And make sure you take decent precautions to cover off (electrically isolate) the opposite pole when you work on the other.

As @WoodiE states changing connectors is not difficult, but if done wrong it can have the same devastating results!

Only do one side at a time and there is little to no risk. Cut, strip, solder, install into connector for one lead and then proceed to the other. Takes a little longer this way but it is almost foolproof. I agree though, lots of ways to short out a pack when swapping connectors.

 

[RcDriver]

So out of curiosity, what happens to lipo battery if you short it out? I checked the lip today and it doesn't seem puffed at all. It looks as normal. I connected it to charger to see the voltage and resistance. They read 4.10v/cell and 3 ohms/cell.

Do I need to discharge it to 0v before throw it in the trash? There are so many information out there but just wanted confirm with the experts in this forum.

I will check the SMC Racing lipo batteries. I heard many good things about them. When I get the batteries, I will test the ESC. Fingers crossed...

 

[chevys10zr2003]

So out of curiosity, what happens to lipo battery if you short it out? I checked the lip today and it doesn't seem puffed at all. It looks as normal. I connected it to charger to see the voltage and resistance. They read 4.10v/cell and 3 ohms/cell.

Do I need to discharge it to 0v before throw it in the trash? There are so many information out there but just wanted confirm with the experts in this forum.

I don't know what happens when you short out a lipo, but you NEVER discharge it to 0 volts. The lowest that a lipo should ever go, whether it's in a car or in storage or anything, varies by who you are talking to, but 3.0 volts per cell is typically the lowest that it should ever be discharged to.

 

[Dex79]

You need to discharge to 0 before you bin it. Once it's completely discharged it is no longer hazardous. To get to 0 I'd guess you will need to use a bulb or something to run it all the way down.
However if it's reading normally I am unsure that there is need to bin it. Someone more in the know than me can clear that up for you.
I do know that you shouldn't leave it fully charged though and it should be put back to storage or drained if it's going I be scrapped.

 

[chevys10zr2003]

You need to discharge to 0 before you bin it. Once it's completely discharged it is no longer hazardous. To get to 0 I'd guess you will need to use a bulb or something to run it all the way down.
However if it's reading normally I am unsure that there is need to bin it. Someone more in the know than me can clear that up for you.
I do know that you shouldn't leave it fully charged though and it should be put back to storage or drained if it's going I be scrapped.

Sorry. I missed the part about throwing the battery away. My fault. Yes, to throw it away discharge it to 0 volts. I thought since it was still reading good numbers that we were talking about using the battery. Sorry again, my fault.

 

[Unusual RC]

So out of curiosity, what happens to lipo battery if you short it out? I checked the lip today and it doesn't seem puffed at all. It looks as normal. I connected it to charger to see the voltage and resistance. They read 4.10v/cell and 3 ohms/cell

I leaned this lesson the hard way as well. And since I have hardcase lipo's (2S 50C) I have these disconnecteable battery leads. And the case is all black...in a hurry on the field...crossed polarity...smoke, pulled the leads out, which were melted within seconds (melt temperature of solder is 275degC). Destroyed the Esc and high voltage servo.

Second mistake was changing a connector to another type on a 3S pack. I thought I did it safely (softpack, fixed battery leads), but in a second the wires short circuited because they both touched a metal plier...

To make a long story short: both packs survived because I was lucky to stop the short circuit within a few seconds.
this happened more than a year ago, and still use both packs safely today.

To check if your package is safe: Make sure it is not swollen (softpack) and you measured a good balance output voltage per cell. Attached it to your charger if the leads are undamaged, but I guess you have to replace the connector. Mine were totally destroyed, not usable anymore. The fixed leads of my 3S package were still in good condition thank god.

After adding a new connector, hook it to your charger and bring it back to storage level. Do this in a place where it is fireproof (lipo bag and/or metal ammo box) and keep an eye on it (as you should always do).
After this recharge it and put it in your truck and test it. I would check the battery every 2 minutes to be sure nothing strange happens.

who knows they can be saved. Lipo's are quite tough to my experience.

But, be very careful!

 

[FPA4]

So out of curiosity, what happens to lipo battery if you short it out? I checked the lip today and it doesn't seem puffed at all. It looks as normal. I connected it to charger to see the voltage and resistance. They read 4.10v/cell and 3 ohms/cell.

Do I need to discharge it to 0v before throw it in the trash? There are so many information out there but just wanted confirm with the experts in this forum.

I will check the SMC Racing lipo batteries. I heard many good things about them. When I get the batteries, I will test the ESC. Fingers crossed...

First, use a lightbulb to discharge them completely down to 0 volt, then cut the discharge leads and twist voltage and ground wires together to ensure there is no charge left in the pack. Finally, wrap them with newspaper and bring them to a recycle centre, trash is a bad idea.

 

[Unusual RC]

First, use a lightbulb to discharge them completely down to 0 volt, then cut the discharge leads and twist voltage and ground wires together to ensure there is no charge left in the pack. Finally, wrap them with newspaper and bring them to a recycle centre, trash is a bad idea.

Only when the pack is really dead!
At this moment they could be still usable!

 

[FPA4]

Only when the pack is really dead!
At this moment they could be still usable!

Agreed, but if the battery has expanded significantly, it has most likely been weakened and could potentially explode while in use (charging or discharging intensely). It may still be usable, but it won't have the structural integrity it had before the short. If you are going to use it, I'd suggest wrapping it in a couple of loops of filament tape to hedge your bets, and make sure you handle it with care.

 

[WoodiE]

It may still be usable, but it won't have the structural integrity it had before the short

Which is exactly why @RcDriver should take this as a learning lesson and buy a new battery instead of risking it. When a LiPo catches fire and it be pretty violent so why risk an RC, garage, house, or even life?

 

[FPA4]

Which is exactly why @RcDriver should take this as a learning lesson and buy a new battery instead of risking it. When a LiPo catches fire and it be pretty violent so why risk an RC, garage, house, or even life?

I could not agree more Woody, it's like keeping that hand grenade you found on the beach as a paperweight and assuming it's a dud because it hasn't gone off yet...

 

[RcDriver]

Thanks for the comments. Actually, I already placed an order from SMC Racing batteries. I looked at some YouTube footage showing how dangerous the lipo can be. Omg, I don't want that happen to me.

 

[lonee]

Yeah, LiPo can be dangerous.
Thats why I use connectors which are makes impossible to connect wrong.
XT90 have an + and - on their plastic part. And I solder the cables one by one to its polarity....
For smaller cars I use 4mm gold contact plugs. One male, one female. That make it also safe.
Just my 1:18 and 1:12 have deans and the 1:36 and smaller the small red BEC connectors...

Just my 2 cents

 

[RcDriver]

Thanks everyone for their comments.

I have been busy lately and finally found a time to play with senton yesterday. I bought 6s SMC lipo (with xt90 connector on it!!) and fully charged it.

I plugged in the xt90 loop connector on one side of esc connector and connected the SMC lipo to the other connector.

?????!!!!!!!

The esc smoked again......this is the 2nd esc I fried. What did I do wrong this time.....?? This is very frustrating.

Please let me know if you need more info or pics