question for lipo gurus.

[wiz310]

I have a Lipo that for some reason has decided to impersonate a dead pig and has bloated to a phenomenal size. It started bloating one day for some reason whilst doing nothing, but fully charged. I used it once and noticed no decrease in performance, or additional bloating. after recharging, I put it away with the others and took it out today to use...........and its huge. all cells are still fully charged and balanced to .2 of a volt. what causes this?. what would happen if I pricked the case and let the gas out?.
I have decided to quit all my electric stuff now because of this phenomenon as the thing would be to expensive to replace on a regular basis, plus I just love my nitro to much. :D

[panzerd18]

what would happen if I pricked the case and let the gas out?.

:confused:


http://www.downforensics.com/Quickstart/ImageLib/explosion-l.jpg

[SNIPE_53]

Man. Get a bucket of water... fill it with a heap of salt. So its very salty water. Get a long stick, LONG!!!! and with a sharp end, stab the lipo. Quickly lift it up, drop it into the water/salt solution and look away. Wait a bit then get some gloves and throw the lipo out.

This method was recommended me by a member of team Flight Power Aus.

[wiz310]

OK...........so what is it that is so reactive?. the gas reacting with oxygen?.
Not possible to let the gas out and then reseal the case.......talking about a tiny sized hole here.

[SNIPE_53]

The electrolyte is unstable i would be thinking...

Google it :D

[wiz310]

yeah.........I guess google is the thing to do. :D

[WOOSHKA]

Is it an ewatts lipo wiz?

[panzerd18]

From what I know which is not much, it will explode/catch fire if you short the cells together light hitting a nail right through all the cells and shorting them.

[GPT]

Simple.Discharge it and then put it in the trash.This is the correct procedure for disposing of dead lipos.

[BulletMaster]

yep, make up a small wattage lamp with a connector (to limit the amount of current flow). Connect to the lipo and discharge. If you are at all concerned, fill a plastic bag with sand and put it over the discharging lipo. Once the lipo is at 0V, it is safe and environmentally acceptable to dispose in the normal waste bin.

Salt water works a lot slower, but can actually erode the electrodes prior to full discharge occurring (electrolysis at work).

Do not prick the envelope.... it can cause an uncontrolled discharge and the thermal runaway situation is what causes the flames and extremely acrid smoke/ashes.

[dusk]

Yep, discharge it until the battery is totally empty, then it becomes just dead weight and can be disposed of in a normal rubbish bin. I usually connect an automotive 12V bulb across the battery and leave it for a couple days. Once the voltage reaches zero, it's ready to be dumped.

I seem to recall that puffing is usually caused through over-discharging and the gas causing the puffing is oxygen. Some people (fools?) have experimented with letting it out. The batteries worked, but had a much reduced capacity and quickly deteriorated to being useless.

Do not poke into a notionally discharged battery with anything metallic. Even though the voltage is small, there is still a lot of energy in there.

[mstone]

You can prick the case with a pin, just don't stick it into the electrode, and let the gas out and reseal with tape. The cell has been damaged and will drop off in capacity quite quickly. This is probably one of the many millions (?) of cells that was make earlier this year with a bad batch of chemicals.

If you have a NiCd/NiMh charger/discharger you should be able to discharge it to zero. Then put it in the rubbish.

I won't post my prefered method of disposing of Lipos but if you are interested search the blabber thread.

[wiz310]

lots of open space here........might be time for some experimentation......MWAhahaha.
it still has a full charge......so Its not a complete write off yet........ but I sense it may be shortly. I don't think it had been over discharged, as it puffed while fully charged and at rest and had enough voltage in it to get my discharger to activate before I charged it. I use the discharger as a rough balancer, and discharge all cells to the same voltage before charging them on my balance charger.

[dusk]

What voltage do you discharge them down to?

[Hytram]

I had one that expanded, pricked with a pin and taped but it lost its charge, so I removed that cell and now use it as a 7.4volt

waste not want not

[dingo]

:confused:


http://www.downforensics.com/Quickstart/ImageLib/explosion-l.jpg
Gee , if they go off like that I`ll come & pick it up . :D

[wiz310]

Gee , if they go off like that I`ll come & pick it up .
If they go off like that........I'm keeping it. :D
I use a discharger that drops the to 3.7V per cell (I think....the one Paul builds)