the full size batteries called for 575 CCA
for the small batteries they recommend 400 CCA
same motor.....my biggest argument is concerning the amount of electronics the smaller battery can produce and handle....no way it can match the bigger battery...those smaller batteries are taking a beating....constantly over heating the smaller plates...which causes them to warp...
like I said - unless you want to add electronics the smaller AGM battery should be plenty, and also much more physically durable than a flooded cell which is very old tech which goes back to the 1800's
If I were needing the larger power I would never go with flooded cell - AGM is a must in my book - vastly superior in every way and much better at keeping corrosion issues in check