Slow battery off gassing or not?

[SpaceCadet]

Are Li-Ions completely sealed or the do they off gas slightly through out their life like Ni-Cad or Lead Acid?
Vaping on my Billet Box I just realized that lot of the air I inhale passes over the batteries which I don't think is a problem in short term but in long term I don't know if they slowly off gas as they age. What do you guys think?

 

[Tcar]

Li batteries do not emit gas in any meaningful way unless something is going very very wrong. A quick perusal of a battery manufacturer's analysis off li battery gas shows it's trace amounts of carbon monoxide, ethane and ethylene gas, which are given off by in tiny amounts and harmless anyways.

https://www.google.com/url?sa=t&sou...QAS5-EJJjPC5t-yMQ&sig2=fYQcm7XYCkVoPxG-47p9tA