LiFePO4 vs TV alternator

[DrSmart]

I know many of you have upgraded to LiFePO4 in your trailer. I'm planning to do the same mainly to power our Residential fridge, furnace and lights in the event of a power outage when on hook ups. Does anyone know what happens with voltages when towing. Say the LiFePO4 voltage is higher than the Tow vehicle charge line. Does the Lithium battery start sending current to the vehicle batteries in an attempt to bring those batteries up to the same voltage as the trailer? Our vehicle has a selectable voltage readout in the information console. Just wondering if anyone has checked.

[RogerR]

I put in 200 watts of solar, over kill for me since I don't have a fridge. But it might be better than worrying about your tow vehicle putting in the amps.

[ARoamer]

Since the lithium batteries have a higher voltage that my TV's lead acid I installed a relay wired so that it only charges my 5th wheel's lithium batteries when the TV lights are on. Or you could simply unplug from your TV if sitting long term / overnight. I also have solar so I'm not dependent on my TV charging them.

[kirkelli]

your Lithiums will not get a full charge from your tow vehicle charge system. You'll be about 12-15% shy of a full charge. If you depend on your tow vehicle to charge your trailer, you should consider getting a DC-DC Charger. Most of these chargers are designed to fully charge the various battery systems.. Also, most RV Charge converters before 2019 are not Lithium compatible, so you should look into TV Charge Converter as well.