LiFePO4 Deep Cycle Battery Replacement

[MADMIKE-JAY]

Hi fellow owners! I have a Jayco 212QB from 2020. It has a smart converter so I can charge both battery types. I have Grp 28 and a Grp 31 lead-acid batteries (roughly 150 Ahr total) that lasts me 4-days of only critical electric use. I've purchased a 48" lockable truck box & 2x 280 Ahr LiTime LiFePO4 batteries w/ a Victron 500A Smart Shunt to mount on the front tongue (just need to move the propane tanks up a little. Now, I'm in the process of cleaning all the mouse crap that got into the power cabinet and under the couch (story for another time).

My question: How am I supposed to FUSE this contraption? Can I just connect the normal power leads to the Parallel batteries even though I've now got 560 Ahr of capacity? Do I need to add an additional fuse in line with the trailer wiring? Will the Shunt serve this purpose?

I always pull in Tow/Haul so sure my alternator and truck battery are fine. Shore power can charge enough to eventually (between trips) get me to 100%.

Next year's project is a 60A DC-DC charger on a dedicated wire from the alternator, a 3000W inverter to run the A/C & microwave off the batteries, ATS for autosensing multiple power sources, and 200W solar.

 

[irwinr]

Will the Shunt serve this purpose?

No, the shunt will not act as a fuse.

I always add a fuse as close to the battery as humanly possible. The fuse should be sized to protect the smallest cables that are downstream from that fuse to the next "overcurrent protection device" (IE: The next fuse/circuit breaker). For example: You may have huge wires coming off of your batteries, but if those connect to a terminal block on the frame of the RV and that terminal block has a smaller 6 GA wire heading to your internal fuse panel: Then your fuse needs to be sized at around 50-60 amps (depending on that 6GA wire's temperature rating. I'd go with 50 to be safe for example)

Most of the newer Jayco's incorporate a self resetting circuit breaker on the cable that connects to the positive side of the battery to take care of this, so if that's the case you could use a larger fuse at the battery with the assumption that the circuit breaker that's already on the frame should be properly sized by Jayco to protect any wiring downstream from it.

 

[MADMIKE-JAY]

Thanks Irwin. I put a 30A in-line on the trailer positive wire.