Hello there again something that ive been researching, it would appear that you need a fully programmable charge controller something like the morning star tristar series, you would need to set the float voltage much lower then the charge voltage, i have been reading on the cruiser forums the with lifepo4 you need to ensure the batteries get a good charge so they must follow the charge profile and reach the 3.8 volt mark roughly, please dont quote me on this but again i say its a safe zone, unlike LFA the LFP range dont mind a 80% charge, the nice thing is they dont need a long float charge time, and effectively harness the power quicker at higher C rate of charge, you want to make sure the battery float is set more conservative, and ensure you have loads on the battery system essentially skimming the top of the power generation .
If you dont have loads, i would really ensure i have a bms system with a smart relay out put, set the bms so that the relay disconnects the PV array when the batteries reach the 90-100% SOC, reason is that once they are full and there are no loads, like the battery system is used at night i would ensure there isnt even a float charge, because the loads effectively wick the excess power generation, you want the loads to balance the scale of power produced vs power used, keeping the batteries in a semi active state, and effectively means that you would charge your float range at 3.50 v per cell or 13.95-14.20 volts for a 12v application and respectively for 25v and 50v applications .
Hence the tristar charge controller can be effectively setup to ensure the float is lower then the cells max voltage and it will have no detriment on the cell structure of heat, as alot of guys on off grid setups are currently running this and effeciently too .
How long it will last is the question, because the few that have been running this setup havent had more then 4 years on its hard to say but they havent lost much capacity and they havent killed a battery yet because its never close to the threshold, it also makes the battery think its never fully charged but also gives it more life cycles, just 20% or 30% less capacity .
again im not professional this is merely my observation .