It's probably not your battery. When the regulator goes, there's no charge going to your battery. Also, the stator is no longer running your bike. This means your bike is running completely off the battery. Not suprising that the battery is dead. It may only need a charge.
Pull off your regulator. It should be on the front of the battery box, under the tank, right behind the rear suspension resevoir. Pull the plug connector off and take a look to see if it's fried. Most commonly, the regulator on R6's go, and fry the plug with it. What you'll need to do is replace that regulator, and if the plug is friend, cut it off and rewire it with spade connectors that you can get at Radio Shack/Home Depot/Hardware Store.
Another thing you should try is measuring the voltage coming off the regulator. Charge your current battery. Now, with the bike off, using a multimeter/dc voltage meter, you should see roughly 12.5 - 12.7 volts off a freshly charged battery. If it's down around 11, your battery was probably cycled to deep and killed off with the regulator. Now, start the bike and hold it around 5k. Measuring the voltage again you should see it jump to around 13.8 - 14.0 volts...give or take. If it doesn't do that, you've eliminated the battery...at least, you know you have deeper problems than that. If it gets to that voltage over 5k, then you know your charging system is fine.
I would then try to get a friend to temporarily "lend" you their regulator to check. I ended up replacing my regulator and rewiring that burnt up plug only to find out that didn't fix the problem. The only next possibility was my stator. I replaced that and with the new regulator the bike was finally charging again. When I pulled the regulator, the plug was burned pretty good. When I pulled the stator out, I had 5 REALLY fried coils. I'm figuring the regulator went and took the stator with it. Either way, you don't know till you dig into it.
Doing these repairs are REALLY easy. I didn't really need that many tools. It took about 30 mins to do the regulator and about 30 mins to rewire it and about 1 hour to replace the stator.
If you have more questions, let me know.
Tools Needed:
Regulator:
-10mm Socket Wrench for top bolt on Regulator
-10mm Open Ended Wrench for bottom bolt (very hard to get to)
For Rewiring of connector
-Spade Connectors
-Wire Cutter
-Wire Stripper
-Crimping tool
Stator:
-5mm Hex (allen) Bit/Wrench - I use the ratcheting Screwdriver with the Little Bits for this.
-Phillips Screwdriver
-Stator Cover Gasket
-Scraping tool to remove old gasket
-Blue or Grey Sensor Safe Silcone Sealant/Adheasive
How To for replacing Stator.