Battery Relocation

[Pontiac1976]

Should be vented (vapors) to a tube going out side the car. (venting out of the car).
No that is for boats. at one time that was ok. To be more safe they do not pass them for Drag racing or cross racing.
The one you sow just keeps the fluid in it but vapors vent to the cab of the car you breath them and can start a fire if there just the right amount of air vapors and spark.
If your doing a car system they might be ok, but vapors will still be in the cab of the car.