Mark ,
I researched the info on the Li fe po4 batteries . There are al lot of types and usages buy
Marine lifepo are built heavier and with more amps and just too heavy to work
Square Bottom lifepo are made to be wedged into the typical battery boxes and come with foam pads to lock them in. they range up to 36 amp hr at 12.6 volts with cca of 500 amps generally 438 watts of useable power each weight about 5 lbs . with 24 batteries that 10440 useable watts at 120 lbs . Phantom battery $250 each
Round Bottom lifepo4 are lightest they have a flanged top (which I think makes mounting easier) . they are 13.6 volts at 28 amps . 525 cca or 380 useable watts. they weigh 3 lbs each. with 24 batteries that's 9120 useable watts . at 72 lbs . aerovoltz batteries $200.00 each
I just used 24 batteries so its easy to estimate different voltages. . I contacted each batteries engineering depts. for real numbers. After researching this for a month I feel the real 3.2 volt lifepo " cell" can be configured for any voltage and designed specifically for aviation power and the price has been droping just during my research Ed Doerr