Vintage Tiger Biggest Battery Size

Hi all
I have a tiger 955i with a duff battery. So new one about to be aquired.
What is the largest physical size battery that will fit under the seat?
I have a yb12 fitted as standard. Would a yb14 fit ok? Or anything else with a bit more capacity.
Thanks

 

thanks, new ytx14bs bought and fitted in no problem. it looks like the ytx14bs is the normal size anyway. the 12bs fitted to mine was too small to start with hence the poor starting and eventual fail after only a year.