… and therein lies the rub. 4x 18650 hits a max of 16.8v at a full charge.
Some of us run gear that tends to get squirrely with it’s ‘magic smoke containment’ at that value. LiFePO4 is a godsend in this case.
At a first reading I had not classified them as reliable because the chinese sometimes shoot amazing characteristics but then it is not true; but then I read the tests and comments, and I changed my mind.
I haven’t tried this myself but according to all that I have read is they do not catch fire except in very rare instances, which I only find one video after the fire. But I read it can happen in rare instances. 
This video shows one catching fire, when these guys throw it in a fire.
This one, they shoot a nail in it.
They have a pretty flat discharge curve even at high current loads.
This is a Lifepo4 chemistry not a Lipo, they are the safest of all lithium cells.
^ I'd catch on fire too if someone threw me in that bin. I need to read more about Lifepo4 as I never knew there were so safe overall.
I’ve been looking at these to use as replacements for 12v and 24v sealed lead batteries in UPSs.
I tired of buying new batteries if the UPS get several hefty workouts. The lead batteries seem to croak at 3 years like clockwork.
Amishbill - I found BMS for LIFEPO4 for 4S and 8S packs.
This guy shows a build and links to parts
I’m kind of on the fence because of the cost.
All the best,
Jeff
you misunderstand the work and the power one cell can deliver
3.2V*8Ah is the total work of 92kJs (25.6Wh)
this means it can drive a 25W motor 1 hour long
max rated power U*C*25
3.2V*8A*25=640W
8Ah and 200A, that means 25C discharge rate, not very impressive to me, a good lipo battery can do 45C fine, and even 90C
the cell volume to surface area is a lot smaller than on 18650 or similar sizes
finally the temperature dictates the continuous discharge rate,
it matters if the cell is built for max capacity or discharge