I have a few lithium-polymer (LiPo) batteries for model airplanes and helicopters that have been damaged or worn out. They’ve been sitting in my garage for a year or two because I didn’t have a good way to dispose of them. I have seen suggestions that discharging the batteries to 0V using a salt water solution is relatively safe, and allows the batteries to be disposed of in the trash. So, I got a plastic tub and filled it with salt water, and dangled the battery’s connectors (http://www.kastwayairsoft.com/Images/products/Batteries/CN-SD-PAIR-med.jpg) into the solution. I left it there for most of the weekend.
Today I went check on it, and have found that the water has turned a murky blue, and there is bluish-greenish, sludgy stuff clinging to the electrodes.
The batteries are discharged (I guess), but what exactly is this chemical that’s been produced? Is it safe to dispose of the water down the drain? I assume the connectors/electrodes are made of copper, or brass, but they do have lead solder joints that connect them to the battery leads, which were submerged as well.
do not dispose of these batteries in the trash. discharging the battery doesn’t make the batteries not hazardous, the claim is bogus. take the batteries to a battery store and see if they have a disposal program. either a store that sells only batteries, the RC store or your government waste/recycling program is the place to take these.
If you used ordinary table salt, there would have been a lot of chloride ions floating around in the solution. I’m not sure whether it’s safe to dispose of this down the sink; I’ll leave that to someone with more knowledge.
Actually, LiPoly batteries are pretty much harmless once discharged. Lead-acid and nickle-cadmium batteries are still full of toxic heavy metals when discharged, but LiPoly , no so much. Still, I prefer to drop my used LiPoly batteries off at the hazardous waste collection place anyway just to be sure.
The greenish sludge is probably some form of oxidized copper or copper salt. It’s probably poisonous to plants and invertebrates. I don’t know what the rules are for dumping those down the drain.
As far as disposal of the batteries go, check your municipal or county website to see if they have instructions for disposal of appliances/electronics/batteries.
