If you haven't already done so, now would be a good time to throw away those troublesome lead battery cable ends and replace them with copper-lug ring-terminals.
Replace the batteries with Group 30S or Group 31S real stud-terminal batteries; you will be happy you did, as life is much easier with stud type batteries.
If you don't have time to be swapping cable-ends, you can still buy the stud-terminal batteries and use the post-style screw-on adapters with your existing cable-ends; this way, you will already have the stud-terminal batteries when you get ready to do the cables.
Where do You find this batteries, is there a store locator?
I will need a pair maybe next year but the prices You say are too good to pass with the addition of the warranty.
Also, does anyone have a pic of the modifications needed to fit this batteries?
Thank You.