Yandina Combiner for Charging Lithium Bank and AGM Bank

[Sheet]

Looking at the possibility of adding a dedicated 12v Lithium bank to run our Multiplus inverter with a small 4000 BTU AC (20a draw). We would like to keep all other loads as they are on the 4 - 8D AGM bank. Will a Yandina Combiner work for charging a 660Ah Lithium Bank w/ BMS and a separate 1020Ah AGM Bank? Would the charge profiles be set to AGM, Lithium, or would it even work. Charging would be from 2 high output alternators (to be determined), Zeus or Wakespeed Regulators, 1500 watts of solar, and occasionally the Victron Multiplus. We realize it would be much simpler to go all Lithium other than starting batteries but have concerns about essential loads running on Lithium - and the AMGs still have plenty of life. Is DC DC the only other alternative? We are new to Lithium and looking for suggestions.

[CaptainRivet]

Originally Posted by Sheet

Looking at the possibility of adding a dedicated 12v Lithium bank to run our Multiplus inverter with a small 4000 BTU AC (20a draw). We would like to keep all other loads as they are on the 4 - 8D AGM bank. Will a Yandina Combiner work for charging a 660Ah Lithium Bank w/ BMS and a separate 1020Ah AGM Bank? Would the charge profiles be set to AGM, Lithium, or would it even work. Charging would be from 2 high output alternators (to be determined), Zeus or Wakespeed Regulators, 1500 watts of solar, and occasionally the Victron Multiplus. We realize it would be much simpler to go all Lithium other than starting batteries but have concerns about essential loads running on Lithium - and the AMGs still have plenty of life. Is DC DC the only other alternative? We are new to Lithium and looking for suggestions.

Why do you have concerns about essential loads....even the cheapest proven lithium battery the brand Li-time is 1000x times more reliable then your AGM that can get a thermal runaway and first create a toxic gas chamber and then cause fire...worst chemistry on a boat...
If you still wanna keep go down to 500AH and simply keep it as backup bank with a selector switch.
I don't know yardinia and if it's capable to charge it or not but most likely not. Charging 2 different chemistry with same charge source requires DC2DC.

Can your multi, assume the 3000 start the AC or do you mean a 12/24V AC? 660AH is a bit tight for that use case....
Why wakespeed or zeus?
A standard external regulator is in 90% more then capable of charging your LFP bank and the manufacturer of the heavy duty alternators normally have their own fitting regulator anyhow.

[Sheet]

Thank you CaptianRivet. That is exactly the kind of thought provoking response I wanted. I did not know AGM was such a liability and was going on the assumption that AGM would be more reliable in the event of a lightning strike for essential loads. I need to research that. Unfortunately we have had two lightning strikes and the AGM's were unharmed but not so much for other electronics. The EMP does a lot of damage and I was concerned the BMS/Lithium would be vulnerable than AGM.??

The Air Conditioner is AC and draws 20amps dc on the batteries when running off the inverter. It will easily crank and run on a Honda 1000 generator or the Victron 3000 Multiplus. I thought 660Ah Lithium would be sufficient but the biggest concern is getting it charged back up and if needed not having to run the engines any longer than necessary.

The Wakespeed and Zeus regulators offer flexible programming for HO charging at anchor while also being able quickly dial back and reduce hp load on the engines when not needed. Suggestions on other regulators?

DC2DC seems to be status-quo to charge two chemistries but it appears to have some current limitations even when multiple units are used. I see some companies offering ACRs or Combiners that are specifically designed to work with Lithium and wonder if they would be a more efficient way to recharge the two banks. From some of your recent post I see you may not be a fan of ACR's. Is the Argofet a better solution?

I've never had Lithium on a boat so please, any suggestion or contrarian views are greatly appreciated.

[smac999]

Lol. Agm is 10x better then cheap China lithuim.

[CaptainRivet]

Originally Posted by smac999

Lol. Agm is 10x better then cheap China lithuim.

Oh really...
Li-time versus AGM
2500 cycles 80%DOD vs 300 cycles 50%DoD (in best case)
Peukert effect 1,05 vs 1,25
Charge efficency 99% vs 85%
Weight difference: 50% lighter then comparable AGM, if you take ratio weight/usable capacity much more
Safety: shuts automatically off if overcharged, to deep discharged, overloaded versus AGM totally unprotected against all this, a faulty regulator is enough to first get a toxic gas chamber then a fire burning your vessel down as AGM gets thermal runaway
Durability: take 150A from a convection oven and make a roast for 30min...the 200AH Li-time will do that 2000cycles, an AGM max 50 if even possible without inverter shutting off.
Costs: Li-time cheaper per available AH

So where is an AGM better or why even thinking of buying??? There is not even the advantage of being cheaper when buying per available AH, without even taking lifespan into account.