best way to discard batteries

Joined
Feb 27, 2017
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Well, it happened, my batteries are starting to give me issues, bad enough to have the voltage drop very suddenly forcing the bird to land, I did the run discharge recharge trick but the worse offender though showed promise for really hot on a hover test and is actually puffy now, was not before the flight, I I'm guessing the battery is now beyond repair? hat being the case, what's best safe way to discard it?