[TenTec] lithium ion batteries or ups?

[denton sprague]

the other day I was at a battery and light shop to get a couple of replacement batteries for one of my ups  units.
I noticed they had rechargable lithium batteries presumable for  cars…very light, small but pricey and had comparable ratings to full sized lead acid batteries…

Wonder if anyone has used these in a ups(uninterruptible power supply) before? 

My station 3kw ups uses a 48 vdc, 76 amp hr vdc battery pack that will be due for replacement one of these days.