Stupid mistake...

[fredo gauvino]

Oh well,

I had always been very meticulous when charging my LIPO pack, but tonight I made a very stupid mistake while charging my LIPO batteries.

Here are the results.

What happened ?
I normally split the battery pack in two to charge one at a time.
I was lazy and did not do this tonight.

After the first half was charged, I tried to connect my 2nd Lipo half to the charger in the dark, but I accidently connected the two batteries packs together.
That is one pack into another pack... :|
It made a very loud clap noise, and I was partially blinded by the light.



It lasted for about ? 1/10 seconds, and the connectors were instantly melted.
The plastic kept bubbling for few seconds...
The wires did not have time to heat up at all.

Since my watt meter was not connected, sorry, I did not recorded the maximum current. :lol:

But I guess that it was way more than the recommended 20C...

I still cannot beleive how stupid this move was, but, Hey, it happened.

Am I doomed ?
Can LIPO battery survive this ?
Or should I throw them away right now ?

The pack seems fine, but I will keep finger crossed !!!

Fred

 

[mwkeefer]

Just make sure those puppies don't short out again and get yourself some 4mm gold bullet connectors with shrouds to replace the ones on there - slide the cover over both wires the solder the proper (male for ground, female for positive) termination on the packs after removing the old ones...

Back in business, it happens to all of us eventually - especially in the dark.

Do check the pack voltage with a multimeter, long as it seems within spec your okay... those connectors are nice in that they will vaporize and usually don't damage the packs.

The problem is you connected them together in a closed circuit + to - and - to + which is the only way 2 packs plugs would fit together..

If you need 2 new sets of connector shrouds and gold connectors - just PM me an address and I can send them to you post... you want faster than normal mail and you can pay s&h (they weigh nothing) - I have about 100 sets on hand and right now HobbyKing shipping seems a bit delayed so... if you need em.

-Mike

PS: you will need a HOT IRON (I use a gun from radioshack) and some aligator hands to hold all this in place to solder them up... it's fairly easy, I can post a video if you want I have some packs to reterminate (not the same reason).

 

[John in CR]

Am I doomed ?

Yes

Or should I throw them away right now ?

No, lipo recycling isn't very good yet. Just send them to me, and I will recycle them for you, free of charge if you cover the shipping.

 

[mwkeefer]

John - shame on you, that's the same crap I pull with about 20 local Radio Shacks to get batteries so they don't have to ship em... but you darn well know his packs are fine... geez, you gonna start selling LiPo via EMS from Hong Kong tommorow?

-Mike

ps; u know im just kidding!

 

[amberwolf]

I'd guess it's probably ok, if it was only 1/10sec. But it's possible a tab on a cell opened up. If the packs have a voltage on them at what's left of the connector, you're ok.

This is yet another reason I use the Anderson Multipole connectors for my batteries (although I started using them because they were the only good safe ones I had). They can't be connected like that; only + could go to +, if they're wired like the connector shell has molded in it. If it werent' for that, I'd've fried a lot of stuff. Back when I started out with small SLAs that used spade flat connectors, I can't count the number of them I melted when not paying attention.

Now, with regular Powerpoles, you could still build a connector that could be plugged in backwards, if you left the leads separate, but if locked together side by side in identical (not mirrored) positions, they'd be safe.

I myself do not believe it is safe to use any kind of connector for power for anything that has, like these, mating pins that can be mirror-image connected, as it allows exactly what just happened to you. If there were different shapes on each one keyed so it would be impossible to fit together the wrong way, it'd be ok. But a connector like the ones you have cannot be made to *not* be able to mate together as you accidentally did, or else they could not connect normally either.

 

[mwkeefer]

Fredo,

A better solution (yes I'll send the connectors needed for this too) would be to make a 2 -> 1 parallel charging cord to go to the 2 packs and then to the charger...

You will need a pair of balance extensions to make a balance tap parallel adapter too..

Then just charge both packs at once, and don't connect in the dark (but you won't need to since you will connect both at the same time and charge just one cycle).

For this you will need

2 x Sets 4mm Gold Plugs to replace the ones on your packs that vaporized
2 x Balance Adapters - What packs are they, 5S, 6S? - used to create a 2->1 JST-HXT adapter
3 x Sets of 4mm Gold Plugs - for 2 Batteries -> 1 Parallel

To use:

Connect the charger side of the cord
Connect each of the two packs 4mm parallel cord
Connect each of the packs balance plugs to the parallel adapter
Connect the output of the balance parallel adapter to the charger
Press Start and Charge them both at the same time.

There are dozens of other methods available to prevent needing to break down the pack, but it's cheap - simple and effective... in a 2 pack situation with a 2:1 cable, I can't see the potential for mistakes durring connect / disconnect.

-Mike

Amberwolf,

He literally plugged one pack into another and I think you could do that with power poles (not going to try with live packs but maybe I'll find the connectors) I've seen people do it... Granted its black to red and red to black so you should see it right but, he did this in the dark- do correct me if I am wrong

 

[liveforphysics]

mating pins that can be mirror-image connected, as it allows exactly what just happened to you. If there were different shapes on each one keyed so it would be impossible to fit together the wrong way, it'd be ok. But a connector like the ones you have cannot be made to *not* be able to mate together as you accidentally did, or else they could not connect normally either.

Actually, one side of these is a male pin, and one side is a female socket, and the houseing size difference from side to side makes it impossible to connect in a homosexual fashion. (male-male, female-female).

The problem here was a common one that many have made, including myself, and I've never had the LiPos be any worse for wear because of it.

Every LiPo cell has the tabs sized to act as a fuseable-link in the event of excessive current for a long enough time interval to damage the cells.

The connector = total failure.

The pack should still be tits

 

[fredo gauvino]

Well it appears that I have no more problems with the batteries.
They burned down my house last night.

No No, I am joking.

Seriously, I am glad to hear that I am not the only one to which this has happened...
I have checked this morning, and the packs are still ok...

Thanks for your connector offer mwkeefer, but I already had some 4mm connectors available, since my pack is composed of 4 HobbyKing Lipo batteries. ( 2S 2P with 4 (6S 5Ah) )
I already replaced the burnt connectors, so my mistake is already fixed.

Have a look at my pack and Y connectors :

You gave me a good idea mr keefer, charging all 4 batteries at the same time would be very practical since it would require less intervention. (me coming back in the middle of charging and switching packs in the dark.)

I would only require to make another Y 2-1 balance connector and charge the 4 batteries in one time.

But this would require my charger to accept 4x5000mAh = 20000 mAh maximum charge !
I have two chargers, one at the job and one here.
The one at home is a iCharger 106B-plus 250W 6s and it can do it, Capacity Cut Off can be set to 20000 mAh.

I think that the Turnigy Accucel-8 150W 7A Balancer/Charger cant.

Ill check monday If this can be done !

I would like a simpler charging solution... All of this LIPO charging sucks.Its called LIPOSUCCION.

PS, John, the shipping is 1250$ Can, you can Paypal me and I ship them to you FREE of charge so you can recycle them. I could also include a FREE prolonged warranty with them if you want.

 

[John in CR]

I sent you one of those Paypal checks, so you can go ahead and ship the packs out first thing Monday morning.

John

ps- glad to see a bit of early morning sarcasm didn't slip by anyone.

pps- Fredo, now you know what is commonly referred to as a plasma flash.

 

[TylerDurden]

pps- Fredo, now you know what is commonly referred to as a plasma flash.

http://en.wikipedia.org/wiki/Arc_flash

 

[amberwolf]

mating pins that can be mirror-image connected, as it allows exactly what just happened to you. If there were different shapes on each one keyed so it would be impossible to fit together the wrong way, it'd be ok. But a connector like the ones you have cannot be made to *not* be able to mate together as you accidentally did, or else they could not connect normally either.

Actually, one side of these is a male pin, and one side is a female socket, and the houseing size difference from side to side makes it impossible to connect in a homosexual fashion. (male-male, female-female).

Ah. I've never used that specific type of plug, but most of the ones I've seen made similarly would easily allow this to happen (not like I'd know from experience or anything )

Amberwolf,
He literally plugged one pack into another and I think you could do that with power poles (not going to try with live packs but maybe I'll find the connectors) I've seen people do it... Granted its black to red and red to black so you should see it right but, he did this in the dark- do correct me if I am wrong

You could do it with powerpoles if they are not locked together in a way that prevents this. But using them locked side by side, you'd be plugging them in + to + and - to -, and at worst there should be a few tenths of a volt difference between them if they're balanced right. With Multipoles like I use, it's the same--they can't be plugged in + to -, - to +, if they're all wired the same. Only + to + and - to -. At least, that's all I've been able to manage by accident so far.

 

[Metallover]

I've shorted my turnigys probably half a dozen times. One of the times.... KFH



PS All my packs are fine, although after one short I had to open up the pack and re-solder one of the connections.

 

[fredo gauvino]

Well it seems that I am a never resting source of new stupid ways of ruining my LIPO batteries.

Nothing bad happened, because I was quick and lucky enough to realize what was happening.
But I believe that it could go very wrong if left like this for a long time.

Here is what I have done :

I connected the battery charger charge 2 wire cable to a 6S battery, and the 7 wire balance cable to another battery.
When I started charging, the charger was showing this perfectly normal values :

3.81 3.82 3.81
3.82 3.81 3.82

15-20 minutes later, the charger still showed exactly the same values...Huh ?

I then realized that I was reading the cell voltages from ANOTHER battery, NOT the one I was charging.
I switched the batteries, and they were already there : :?

4.04 4.05 4.04
4.05 4.04 4.05

I wonder if the charger would have been smart enough to stop the charging process once that total battery voltage would pass 25.2V, or it would dumbly try to balance each cell and keep up charging, and overcharge them ?

Anyone had tried this ?


Moral : Always break up your battery packs before charging one at a time.