Not too clued up on Meta, but isn't there a reset that you need to do if the bike has been left for a certain time??
Might need resetting after you swapped the battery over?
I think you need the killswitch on (run), sidestand up if you have the safety cutout, hold the alarm button down and turn the ignition on............whilst still holding the fob button down until it comes back to life...........phew.
you might need 4 pairs of hands to
Other than that, check your main fuse. In the fuse box, rhs frame tube. Could've popped it when you swapped the battey over.