Holy sh*t Batman! You were luck that the battery pack didn't 'POP' in your house.
Let it sit outside for about a week and then just toss it in the trash, BUT KEEP IT AWAY FROM ANYTHING THAT YOU DON'T WANT TO BURN DOWN until then. You may want to check the mfg recommendations on disposal though..
I personally never liked those EC3 connectors. I've swapped all my stuff over to Deans Ultra which seem popular.
I'm looking hard at that Airfield Corsair myself.