Which of the following statements about LV battery packs with lithium based chemistry other then LiFEPO4 is not true?

1. They must be in a rigid and sturdy casing
2. They must be enclosed in a non-conductive, waterproof and acid resistant containerCorrect
3. They must be protected from short circuits, not more then 100 mm from ungrounded terminals
4. They must include overcurrent protection that rips at or below the maximum specified discharge current of the cells