I own a comet myself and i can tell you that getting the OEM battery is next to impossible now. Its not kinetic anymore and i haven't seen too many Mahindra 2wheeler showrooms/service points. Almost all the old Kinetic showrooms have shut shop in pune except city motors i think.

So the best thing would be to try what people are suggesting:
1. Try finding a 12v 12AH battery. Its a really tough job but if you do find it, you are good. The 9AH battery does work since i've used it exactly for 2 weeks before kinetic could get me a replacement for 6k.
2. Try the RE battery. I own a bullet as well but never tried. Hmmm..maybe i should cause then i will know when my (2nd) stock battery decides to die on me.

Check Battery of the Light commercial vehicles. If the size suits then 12 amp battery may be available.

Thanks for those suggestions...
But the main problem from what I've learnt is that accomodating the RE's battery is very hard because the comet's battery box is a very compact thing it seems..

Give me the dimensions of comet battery (H X W X L), I have one dead 12v14Amp/h battery in my workshop from Royal Enfield, so I will check the dimensions...

Well , since even I am on the lookout for a bettery for my Aquila, I took out the existing battery and tried looking into it for clues !!
Sure the battery says Hyosung, but look closely and you'll find that Vision is written on it !!
And the model number is Vision CP 12120, 12V 12 Ah !! I looked arnd and this is indeed a Chinese battery manufacturer. They have the exact model number CP12120 listed in their products.

I looked into Justdial services and found a cupl of dealer in Mumbai and Pune hu sell Vision. Couldn't find any dealer in Bangalore, which is a shame really ! So maybe people hu need Comet/Aquila batteries can have a lookout in Pune/Mumbai and see if that battery can be found.

Also Pune xBHPians, can you pls check and see if there are any battery dealers there who sell Vision batteries !!

Also for people hu wanted to know the dimensions of Hysoung battery. Assuming it is indeed Vision CP12120 , its 151x98x91, with the total height of the battery being 101 mms !!

And that kind of bring me to my next question especially with people like Sumit/ Prabhu who have used alternative batteries on their Comets.

I have seen Yuasa YTX9-BS battery as listed to be comaptible with Comet/Aquila. And found that Bachoo motors in Mumbai can send it across to me. But my question is, since that is a 9Ah battery, how will it handle the bikes. Since the original is a 12V 12A one. I guess both Sumit and Prabhu have used Pulsars 9Ah batteries.
How were they ? Do they create any cranking problem, or low light beam or something ??
Also do you think they'll fit cleanly into the battery box ? Yuasa YTX9-BS has an overall height of 105mm, as opposed to 101mm of Hyosung/Vision CP12120.

I myself have not yet got a chance to look into the battery casing to check any extra space on top, but I'd assume its pretty compact !!
Tx in advance for the reply guys, wich I need a bit urgently as my bikes just sitting like a duck now !!

enquired a few comet owners, most of them r using Exide Backer battery which is 12V 14A for a comet. they said that its a perfect fit n works like a charm. how abt it???

Bumping this up. Anyone with an Aquila or a Comet, which local batteries are you using?

"Exide Backer battery which is 12V 14A for a comet"doesn't that help or looking something more precisely!! ANd i guess we have btteries with 12v 14V in market.

The backer had stopped production from what I was told. Also the backer required you to chop a small part of seat for it to fit. I wanted to check if they are any approrpriate 12V 14 Amp batteries in the market since I last checked