Another Alternator charging question

I have a small toy hauler that I am adding a 400w solar/300ah 12v lifepo4 system to. My tow vehicle came from the factory with a 150 amp alternator, dual batteries and a 1000w inverter. The truck was setup up from the factory to provide charging power to either a camper or tow vehicle. I know the system is designed for lead batteries is there a way to convert it to be safe with lifepo4. Would it be better to disconnect the trucks charging system from the trailer? Also the lifepo battery I am using has a charge limit of 100 amps.

You're going to want to look for a DC-DC charger that is lithium compatible. That'll ensure the power being passed to your lithium batteries is corrected to the right voltage. They're available from Sterling, Renogy, and now even Victron.

Add a battery to battery charger to your trailer. Check out the renogy branded ones that can also act as your MPPT controller. Less stuff to install and will protect your alternator. 150A isn't that large these days...

I'm not certain which would be better yet but I disconnected the trailer 12VDC feed on the trailer side so the MPPT solar charge controller has full control of the charging process when towing. 4 FLA GC-135's voltage cutoff set to 13.5.