Likewise my lead acids have given very little or no notice to failure.
If the claims below are even 50% correct the lithium are the way to go.
• 18 month Shelf Life
• Up to 80% lighter than Lead Acid Equivalent
• 5X the Life of a Lead Acid Battery
• Quad Terminal Configuration for ease of installation
• 2000+ Deep Cycles at 80% Depth of Discharge
• Can be mounted in any direction
• Lithium Batteries do not sulphate
I was lucky enough to get mine for $75 USD don't think I can loose.
I think the 480 is $70 dearer than the 360.