Lifepo4 Batteries

[Midnightsun]

QR_BBPOST So your alternators go to your isolators, which feed your house batteries, which then feed your lithium bank via the DC-DC chargers? Is that right?

Correct.

[KyleR]

Thanks! Couple more questions if you don't mind:

The way my system seems to have been designed from the factory is that there is also a feed from the port isolator that goes to the house battery to keep it charged from the alternators while underway. It seems to me this wire has to come off otherwise the alternators still have a direct charge path to the lithium bank. Did you run across this same setup?

Also, since my alternator sensing leads currently run to the house bank (currently flooded lead acid), it seems I should remove it from the house bank and instead run it to the applicable starter battery. Does that sound correct?

Sorry for all the questions but I want to make sure I get this right from the start and don't damage anything or have to do rework!

[Midnightsun]

Yes on both accounts. No communication between LifePo4 bank and Lead Acid bank. My isolators were set up the charge between 3 banks (start, start, house) , I simply disconnected the lead going to the house bank. This way I had a fall back plan if I overlooked something and needed to go back to lead acid house bank. Nothing to report that would have me do so.

[KyleR]

My thoughts exactly. And I'm glad to hear there were no unforseen consequences. Thanks again!!

[KyleR]

To close out my part of this thread, I ended up going with the Victron Orion XS 50amp DC-DC Charger. I came off my STBD starting battery through a 60a breaker, to the Orion XS, through another 60a breaker and then to the house lithium bank. Works perfectly and keeps the house bank charged while underway. Thanks to all who chimed in with their experiences and wisdom! Kyle

[mikesparker]

Kyle, I know the Orion XS is a great DC/DC...I'm curious about why you went with 60amp breakers if it's only a 50amp charger? Also, why only 1 charger instead of the 2 as per midnightsun? I'm installing a LifePO4 setup next month and have some decisions to make!

[KyleR]

Since it is designed to pass 50amps, I wouldn't want to use anything less than or equal to 50 amp, thus I went with a 60amp breaker. Plus, it is what is recommended by Victron in the product documentation.

Each of my alternators feeds it's own isolator, and both of my isolators are cross connected. With this setup, if one alternator goes out, the other alternator will pick up the load. So, no real reason to have two DC-DC chargers. I have confirmed proper operation by running only the port engine and got proper charging, then I ran only the starboard engine and got proper charging.

Hope that helps!

Kyle

[mikesparker]

Ok that makes sense. So forgive the ignorance here, but would two 30amp chargers putting out a combined 60amps be advantageous? Or does the efficiency of the XS make up for the 10 amp "deficiency"?

[mikesparker]

QR_BBPOST To close out my part of this thread, I ended up going with the Victron Orion XS 50amp DC-DC Charger. I came off my STBD house battery through a 60a breaker, to the Orion XS, through another 60a breaker and then to the house lithium bank. Works perfectly and keeps the house bank charged while underway. Thanks to all who chimed in with their experiences and wisdom! Kyle

Can you confirm that you came off your STBD HOUSE battery and not the starting battery? I'm confused...lol

[KyleR]

Can you confirm that you came off your STBD HOUSE battery and not the starting battery

Excellent catch!! Yes, I came off the STBD STARTING battery (not house). I just corrected the original post. Thanks for pointing that out - that definitely would create confusion!