leaking battery on my shoprider vienna powerchair,

Hi, The battery on my shoprider power chair is leaking. Only an occasional drip (once a fortnight maybe). But it's acid! My only indication was to see a drip sized hole in my carpet! Now there's a few. Am I missing seeing some indicator light or something to say this is likely to occur - before ruining my next carpet?
The battery is only two years old. Of course, I'll replace it but can I be sure this carpet-ruining form of indicator won't happen again?
Why's this happened?
Is it a really rare event out there?
Why are there drain holes in the battery cover? (is it to let the acid out - strange if so.)
Grateful for any advice, I'm anxious to solve this before I invest in a new carpet.

Found a site that maybe helpful to you with a link to a site about the batteries. Also they say get rid of the battery a.s.a.p.!! So here is the link to the advice site!!

www.candlepowerforums.com/vb/showthread....leak-Is-it-dangerous

You need to buy gel batteries and you wont get this problem anymore!

Do you have any sort of insurance you can claim on. Unfortunately I only have insurance for damage to other people when using. Can you get insurance to cover wheelchairs and damage. They can cost as much as a car!