Battery vent - necessary?

[jmsgld]

I look after a foreign neighbour's DB7 and 06 plate petrol Mini whilst they are away.

The Mini needs a new battery, it still has the original BMW one in it with a vent tube.

Another neighbour is a manager at TPS so I normally get him to get my batteries for me. The replacement he has doesn't have a vent.

Is this an issue? Presumably it's just a sealed battery that doesn't need a vent, or is there something particular to BMW's that their batteries need venting?

Many thanks, James

[jmsgld]

Suggested battery from TPS is a Yuasa 3027

[anonymous-user]

Yes it absolutely needs venting and this person has answered the question best on this site:

http://www.boats.com/how-to/sealed-batteries-still...

[jmsgld]

Thanks for the link.

The battery is under the bonnet so I would have thought enough ventilation?

I can't say I have vented another battery I have replaced recently...

[helix402]

You’d be surprised how common it is for people to change a BMW battery and bin the vent pipe. I once owned an E36 328i where someone had done it. The area beneath the battery was corroded as was the inside of the rear 1/4.


My current 330 had no vent pipe when I bought it, fortunately no damage done, but I’ve fitted a vent pipe now.

You sometimes need to swop the vent pipe from one end of the new battery to the other to fit it.

[anonymous-user]

jmsgld said:

Thanks for the link.

The battery is under the bonnet so I would have thought enough ventilation?

I can't say I have vented another battery I have replaced recently...

Under the bonnet? Sufficient ventilation so no vent required but you need to grease the terminals with copper grease or something to help prevent corrosion. Anything waterproof and non electro-conductive works so long as it is removable.