battery transport bungs

[dmccormick]

Just got a new battery for the wife's car and it has a warning label on it saying remove bung(s) immediately. Battery web site says "remove these immediately".

However, I am wondering if I really need to remove both of them or just one - the car has a battery breather tube that fits into the hole on one side of the battery.

If I remove both bungs then there doesn't seem much point in the breather tube because the hole at the opposite side will just be open directly to the engine bay. Doesn't seem to make sense ?

Should I remove them both or just the one where I connect the breather tube ?

 

[Diyisfun]

If the battery web site has a 'contact us', then contact them & ask them.

 

[dmccormick]

Yes, I've done that, but I am not holding my breath for a reply and was hoping this would be an easy question for the forum.

The battery is a Varta E11 so very common and nothing unusual.

 

[Spark123]

The hole is just for the battery to vent when charging as hydrogen gas is given off. If it can't vent then pressure can build up leading to an explosion (as Mercedes Benz found out a couple of years back when they had a faulty batch without vent holes).
If there is a path through from one side to the other then I don't see why you need both removed as the hydrogen is only given off slowly, especially if you only have one breather pipe as removing the other bung will allow hydrogen seepage into the battery compartment.

 

[dmccormick]

Thanks. It's what I thought as well, but the battery web site replied just saying remove both bungs. I guess I'll leave them both out just in case there is some kind of central divider that stops one side connecting with the other.

 

[Spark123]

Bit rubbish if, as in some cases, the battery is in the boot though
One easy way to test to see if there is a throughput is to stick a small pump (I don't recommend using your breath disclaimer) onto one side and blow through, if the air escapes the other then there is a path through.