Please be aware the purpose of this vent tube isn't just because the gas emitted from batteries might smell and become unpleasant but because this gas is hydrogen and becomes explosive with as little as 4% saturating the air. In the case of a broken charging system could also produce hydrogen sulfide which is poisonous AND flammable. The placement of the battery being enclosed with little to no air flow means the gas could build up to levels that can become an explosive fire hazard in the event of a spark or flame in the area which is always possible when handling the battery. Any battery in an enclosed area needs ventilation to maintain safety regulations. Most car batteries are under the hood and are therefore already vented so most people have never considered this or have even seen a "vented battery". If you need to access your battery and notice you don't have the vent tube connected just let it air out for a minute to minimize risk and always remove the negative terminal first.

 

Okay, liability absolved AGAIN. That gets done every time the subject comes up.

I drove air cooled VWs for 15 years and still live.

 

The two 6 volt non vented batteries in my MGB GT didn’t make any funny smelling fumes! And it didn’t blowed up, real good! Neither.


just for entertainment purposes!