Vent tube on BMW battery. Why?

[propellerhead]

The battery on my spousal unit's 2000 BMW 323ci died at a bad time on Sunday and I ended up replacing it with a $50 regular battery from Autozone just to get us home. The original BMW one had a vent tube. The one I put in did not.

How critical is this vent tube? Any technical info on this? Aren't new batteries sealed units? Do they still need vents?

Link to pics similar to what I had: bimmerfest

 

[Asharus]

The vent tube is connected to the battery's exhaust, so it will not stay inside the car. The gas that is emitted from the battery is explosive.

My battery is under the rear seat, and is connected to a tube as well. Those batteries come w/ a tube and adapter. I bought one about a year ago, and had to go back to grab one off of another battery.

Is the battery in the E46 your wife has located in the rear seat as well? I thought the 3's batteries were in the trunk.

 

[propellerhead]

It's in the trunk, passenger side.

 

[woowoo]

Sounds like you DO need to vent.....

 

[alkemyst]

The only way around venting an internal to the cabinspace battery is going with a sealed gel cell like optima and the like. You can search M3 and miata forums for options.

 

[TerryMathews]

Placing a non-sealed lead-acid without a vent tube battery anywhere except under the hood is a fatal mistake. Lead-acid batteries that aren't sealed give off toxic fumes when charging. The alternator in your car ensures the battery is always charging. Game set match.

Get a battery with a vent tube hole, or invest in a sealed battery.

 

[propellerhead]

How bad are these fumes? Does it trickle out like a leaky faucet? Does it dump out like the engine exhaust? Would it be ok to drive with the windows open for a week till I can get a vented one? Or is it like stop now, get out of the car, and walk away from it?

 

[Asharus]

Originally posted by: propellerhead
How bad are these fumes? Does it trickle out like a leaky faucet? Does it dump out like the engine exhaust? Would it be ok to drive with the windows open for a week till I can get a vented one? Or is it like stop now, get out of the car, and walk away from it?

You can wait a week or so...

 

[Xionide]

Originally posted by: Asharus
The vent tube is connected to the battery's exhaust, so it will not stay inside the car. The gas that is emitted from the battery is explosive.

My battery is under the rear seat, and is connected to a tube as well. Those batteries come w/ a tube and adapter. I bought one about a year ago, and had to go back to grab one off of another battery.

Is the battery in the E46 your wife has located in the rear seat as well? I thought the 3's batteries were in the trunk.

The e30 318's are in the engine compartment cause there is room on the 4 cylinders.