Damaged Lipo, Disposal?

[Arct1k]

** DISPOSAL OF LIPO BATTERIES **
Unlike NiCd batteries, lithium-polymer batteries are environmentally friendly.
For safety reasons, it’s best that LiPo cells be fully discharged before disposal (however,
if physically damaged it is NOT recommended to discharge LiPo cells before disposal -
see below for details). The batteries must also be cool before proceeding with disposal
instructions.

To dispose of LiPo cells and packs:
1. If any LiPo cell in the pack has been physically damaged, resulting
in a swollen cell or a split or tear in a cell’s foil covering, do NOT discharge the battery.
Jump to step 5.
2. Place the LiPo battery in a fireproof container or bucket of sand.
3. Connect the battery to a LiPo discharger. Set the discharge cutoff
voltage to the
lowest possible value. Set the discharge current to a C/10 value, with “C” being the
capacity rating of the pack. For example, the “1C” rating for a 1200mAh battery is 1.2A,
and that battery’s C/10 current value is (1.2A / 10) can be used,
such as a power resistor or set of light bulbs as long as the discharge current doesn’t
exceed the C/10 value and cause an overheating condition.
For LiPo packs rated at 7.4V and 11.1V , connect a 150 ohm resistor with a power rating
of 2 watts (commonly found at Radio Shack)to the pack’s positive and negative terminals
to safely discharge connecting it to an ESC/ motor system and allowing the motor to run
indefinitely until no power remains to further cause the system to function.
4. Discharge the battery until its voltage reaches 1.0V per cell or
lower. For resistive load type discharges, discharge the battery for up to 24 hours.
5. Submerse the battery into bucket or tub of salt water. This container should have a lid,
but it should not need to be air-tight. Prepare a plastic container (do not use metal) of cold
water. And mix in 1/2 cup of salt per gallon of water. Drop the battery into the salt water.
Allow the battery to remain in the tub of salt water for at least 2 weeks.
6. Remove the LiPo battery from the salt water, wrap it in newspaper or paper towels and
place it in the normal trash. They are landfill safe.


Basically if not knackered take voltage to zero else do the salt bath...

I'd hate to be that person who brings down a 747 with a lipo fire... I'm sure the odds are tiny but thats just me...

[JThiessen]

I gotta weigh in on the side of caution here. You will be shipping something that is potentially explosive. There are proper means of doing this - contact your shipping company of choice, and they can tell you what it would take to safely ship this item. It may end up being prohibitively expensive. Maybe getting an ammo box at a surplus store, and ship it in a lipo sack would be sufficient. The weight of the box will drive up your cost, but it'd be safe.

Now, on the other hand, if one of those jumbo's does go down, it'll likely mean another order for us, and I'd love to build another airplane! Just kidding......the fire suppresion systems would quickly have that fire put out, and all we'd have is a few soaked and charred packages - and more than one unhappy customer.

[lincpimp]

I guess the salt bath is the best way to completely discharge a lipo. A std nimh light bulb discharger is definately not safe.

As far as shipping goes, a properly padded package should be fine. Tape the holes with something non conductive and the same with the tabs. Unless the lipo shorts it will be fine. Remember that we ship non dmamged lipos all of the time, and the same sharp object could stick thru the package and cause one of them to catch fire. Caution is fine, but blind paranoia does not do anyone any favors.

[JThiessen]

Originally Posted by lincpimp

Remember that we ship non dmamged lipos all of the time, and the same sharp object could stick thru the package and cause one of them to catch fire. Caution is fine, but blind paranoia does not do anyone any favors.

So is a damaged lipo considered as stable as an undamaged one? Not arguing, just wanting to know.

[lincpimp]

Originally Posted by JThiessen

So is a damaged lipo considered as stable as an undamaged one? Not arguing, just wanting to know.

Honestly if the cell is not puffed it has not undergone the chemical reaction that produces the gas that may makes the cell casing puff/pop. As far as lipo fires go, the internal anode and cathode must touch, or arc in some way to get the litium to ignite via extreme heat. I have had cells puff from overdischarge, and seen what happens when you over charge one (hooked a 12v car battery to a 1 cell lipo with jumper cables in the yard, it made a pop noise and smoked a bit).

As far as shipping goes, as long as the pack is not puffed, and does not have any method of shorting the tabs it should be just as safe as a new lipo. That means that if you stick a screwdriver (or something sharp) thru either it will produce the same result (some smoke and heat). I have had torn case cells hanging around for months, all they do is smell a bit sweet (must be the paste inside) and take up space. I have read may different ways to dispose of lipos, and the vast majority just say to snip off the tabs and toss them in the garbage.

I have thrown them on the ground, stabbed then, run over them with a truck (f250) and never got anything until I hooked up the car battery. I have had worse smoke and heat from nimhs going bad....

[JThiessen]

Good info.

Originally Posted by lincpimp

I have thrown them on the ground, stabbed then, run over them with a truck (f250) and never got anything until I hooked up the car battery. I have had worse smoke and heat from nimhs going bad....

Why do I suspect some of the above were intentional?!?!

[lincpimp]

Originally Posted by JThiessen

Good info.



Why do I suspect some of the above were intentional?!?!

I have abosolutely no idea why you would think that...