Do SLA batteries sulphate?

[Footie]

I have a question about lead acid batteries that I was hoping the forum members may be able to answer.
Through out the forum it is regularly stated that lead acid batteries sulphate, which effects there charging ability.
I was talking to a work colleague the other day about lead acid batteries and he disputed this by saying sealed lead acid batteries and/or the gel type don't sulphate because they are in a gel and sealed. This seems to be in contradiction to the information I have obtained on the forum about lead acid batteries.
I don't know enough about batteries to argue the point.
Where the battery is sealed or in a gel does this stop the battery plate’s sulphating?
Is my work colleague right or wrong?
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[pete22]

Useful link here: Lead Acid Batteries

There is a section on sulphation causes.

 

[HarryB]

I am sure your work friend is wrong. It doesn't matter how the sulfuric acid in the battery is contained, even if it is sealed or in a gel the battery will still sulphate if it is left discharged. Batteries are sealed or in a gel because they are safer to use in certain applications (but it does not help with reducing sulphating of the lead plates).

 

[flecc]

As HarrryB says, the sulphating is still present, the gel construction being only for physical stability in any orientation.
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