Capacity and cold crank amps are different qualities of a battery... For a large Twin I'd go for the biggest number on the CCA, assuming they are measuring the same; as it would give the fastest spin up. The capacity would give you more goes at starting. Another most important quality is that it can be secured (it fits) and that also that the + and - terminals are in the right place (not swapped or on the other side).
You are restricted by the size of your battery box. If you have more space, something like a YT12B-BS will give you a bigger capacity but you would need to check that your generator has enough output to keep up with the discharging whilst riding. Andy
It has also just occurred to me that if you change the model of battery, your leads need to match the new terminals which are not always the same orientation. Andy
IMHO the generator will be able to cope with any sized Lead Acid that would fit the space, as the draw would be proportional to the voltage of the battery. The amount of draw on the generator would be the same for any lead acid battery, for the same state of charge. I already said that in post 24...
Not got a recommendation but i'd steer clear of the motobatt stuff. Bloody terminals aren't fixed to the battery, more stuff to vibrate loose.
I've had good results with Motobatt, admittedly I like the fact we can buy a battery with '4' terminals, so we can swap sides for use with other bikes...(my KTM is +ve on the left) the bolts have serrated teeth to grip the terminals. The other thing to consider is weight, as it can be quite a high percentage of the bike weight...If you up-rate the starter cables you could potentially go with a lower CCA - and hence a lower weight battery. I did this with my superlight.
... based on my experience of myself and others on this forum, sizeable weight savings can be made elsewhere.
I swapped the standard Yuasa YB16AL-A2 - weight with acid: 5.3 Kg with a Motobatt MBTZ14S - weight: 3.4 Kg with no issues on my 900 superlight (With uprated cables throughout the bike) Plus the smaller form factor leaves a nice space for the digitech ignition. I figure losing 2kg with no effort at all...not even a pre-ride dump..is worth it! Cheers! Grant
Halfords don't stock the' high performance' in that size, it's just a standard Yuasa - maybe they don't do one at all...