What happens if I try to charge a LiFePO4 battery from the car alternator?
I have a X30 LiFePO4 battery (https://cara-tech-24.eu/en/electric/278-powerxtreme-x30-battery-lifep04-battery.html) in my caravan. Currently it's only being used for the mover (electric motor to move the caravan to the exact spot)
It is not used for the internal 12V lights in the caravan, which can be powered from the car or from mains from a SwPsu in the power distribution.
I want to connect this battery to the internal lights; the simple method is to wire it in parallel with the power from the car, either directly or via a DC/DC-converter to boost the voltage to compensate for the wiring losses.
But would that be bad for the LiFePO4?
Should I settle for a switch (relay) to either feed the internal lights from car or LiFePO4, and only charge the battery when connected to mains?
EDIT: A test showed the battery in two hours with all lights on only used 25% of the battery. As our use case would never be 8 hours in caravan with full lights on, but no mains power, I decided only to charge the battery from the built-in charger, skipping adding a DC/DC-converter for around €120.