lithium ion battery requirements

[GS1150Pilot]

The one I installed has 60 more CCA than the AGM it replaced.

[Greg B]

I installed a physically smaller Shorai battery in the 1150. No other changes to the charging system.
I had to go with a smaller battery because changing the swingarm to a braced calfab arm from a GS 750 changed the upper travel of the linkage such that it would have smacked the original battery box.

[salty_monk]

Lithium are always rated as an equivalent - that's because the discharge is different.
A lithium will output nearly full voltage until it's very flat (and then go totally dead). An AGM or lead acid will taper off more slowly so you can't use the full capacity of the battery (as the voltage is too low even though that there is lots of raw energy still in the battery).

You do need at least the same CCA as the original battery (most AGM are rated higher CCA than the original lead acid too). More is fine. You will likely find the smaller one will work (people have used very small batteries on GS customs) but you need to make sure that there is adequate reserve (these bikes do not really charge at idle although with the stator with the extra winds on it from Elektrek they do).