Not all LifePo4 battery chemistry is the same. When I fitted 2 LifePO4
batteries to my 27 I chose A123 because of their chemistry and BMC. See
he https://tinyurl.com/ybmof8qh

Unfortunately theses batteries were only 4.5AH but because of the way the
voltage stays good until the BMC shuts the battery down I have never run
out of power.

Also unfortunately, I am not sure that the 12V7 form factor is still
available so I am hoping that the rated 5000 cycles will see me out!

Jim