Minch,I got the ricks motor sports reg/rec that goes to about 14.2. I just wanted to know if the 4cell is strong enough to start my 450.
I would try E-mailing the battery manufacturer. You will need to be able to tell them the cranking amps needed and the alternator output. Would also be nice to give them measurement for the space you have. . We have doing this by direct contact with the US supplier for one of these companies for about ten years now. We are using lithium batteries in all our racers from a 1980 Moto Guzzi to a 2015 Yamaha R-6 with only one fail. The fail was with my Triumph 2004 Thruxton daily rider. The Triumph cooked two batteries in a row. Back to lead/acid.
I will tell you that one of the smallest lithium batteries that I could find starts a V-twin Superhawk engined bike over and over and has for the last four years. Now this engine is always in top tune so it starts quickly but as long as you flip the key to on and let it warm up before you try and spin the starter it cranks right up turning over rather quickly.
One last thing as I am in no way the authority these super light batteries. I always put the bikes on a charge when they are parked (street bike, race bike, doesn't matter. Nor does it matter how long they are going to sit) and I always use a lithium specific charger on the lithium ones, Just saying use the right tool for the job.