12V UPS Design for Motorcycle

Working on a 12V battery backup system for charging while on the road and when stoppe don my motorcycle for a lot of the long distance touring i do. Please take a quick look at the following schematic and let me know if im on the right track.

The system should only connect the additional battery and loads to the motorcycle charging system when switched power is active on the inputs and drop off/run the loads on internal battery when the motorcycle is turned off. Basicly a small UPS system.

Any insight is appreciated!

Your circuit connects the motorcycle power system to the battery when the relay is energized. When the LiFePO4 battery is deeply discharged, this will potentially draw enough charge current to blow the fuse and possibly damage the battery.

Also, most LiFePO4 batteries also need a more highly controller charger than is provided by a motorcycle generator/alternator. They are not as cantankerous as Lion/LiPo batteries but poorly controlled charging will limit the life of the battery.

There are buck-boost chargers available that will properly charge the battery from either the motorcycle alternator or an external power source (I think batteryspace.com sells at least one).