Hi mate yes I do use a lipo sack not so much to charge ( I dont leave them unattended while they charge) I do store when charged or at store charge , I got mine from Hobby king the biggest sack will take 4 batteries and charger board at once , And a very big YES to are they dangerous
Do you need one bag per battery or do you store all that are not being used in one bag?
What about charging 5 or 6 batteries at once? All in the same bag while charging?