I always had the impression that Li batteries had a relatively short useable lifespan. You could potentially have to replace this battery more often than a traditional dry cell unit. Do you have any info of how man cranking amps the battery will supply in it's degraded capacity? What about the heat generated from not only hot sunny days, but the engine as well, Li doesn't like to be hot at all. What about general maintenance, any special concerns that need to be addressed?
I'm not saying it's a bad purchase, just would like to get some facts together.
It sounds like you're familiar with "LiPo" batteries, which are really Lithium Cobalt Oxide (LiCoO2)
These batteries are Lithium Iron Phosphate (LiFePO4) rather than the older LiPo chemistry from R/C vehicles, laptops, 787s, and so on.
They're a lot safer - they don't catch fire easily or burn well readily if short circuited or overcharged like a LiPo will, which is why they don't need an expensive built-in charge management system for auto use.
Additionally, LiFePO4 degrades MUCH more slowly than older-style lithium polymer batteries. The lifespan to 70% capacity is often cited as 7 years, and they don't degrade rapidly when warm or 100% full like a LiPo will.
With that being said LiFePO4 batteries have only really reached normal market channels in the last 3-4 years, so there's not a lot of anecdotal data about how long the batteries sold for automotive use actually last. I've had a set of two LiFePO4 cells in an electric bike I built a few years ago and they've held up great so far.
