I think it might be worthwhile to have a marine electrician study your installation, understand your objectives and then provide a design, as there are many considerations that will impact the effectiveness and safety of the upgrade. Given the costs, you certainly don’t want to do it twice. Some companies (i’m not affiliated), can do some remote systems design if you can provide basic information on your current setup. There’s a steep learning curve to adding lithium, converting some systems to 24V adds to the complexity. Electrical Consultation & Design | Pacific Yacht Systems
What loads will remain on 12? I would imagine you’d only have LED lights and basic electronics, 12V/USB outlets, I can’t imagine this adding up to 50 Amps @ 12VDC? If you’re going through the trouble of moving to 24V for storage, then ideally your fridge, bilge pumps, bow thruster, anchor windlass, etc.. are already 24V capable or would be moved to 24V.
If you need to spend 10 grand or more converting equipment to 24V, I doubt having a 24V main bank is worthwhile. In that case, you’d be better off sticking to 12V main bank, ensuring you have a short wire run and appropriately sized wires for the two inverters. I have a Victron 3000VC (which by the way, is only a 2200 Watt inverter), about about a 22 ft round trip run from the batteries, to the always on DC bus then to the inverter (total length of positive and negative wires) and voltage drop is NOT an issue.
Are you 100% sure your 120V AC units will run on the 3000VA inverter? Pay careful attention to the constant and peak (startup) power requirements. You may need to install hard start capacitors on the AC units to use them with the inverters without triggering the over current alarm / shutdown. I’d check with your electrican that he’s seen your AC units work with the inverter you’ve selected.
What is the min circuit ampacity of your AC units?
Do you have space for a seperate 24VDC panel? You’ll now need a 120V (240 V?), 12V and 24V breaker panel, along with monitoring systems.
170A alternator, depending on how you use the boat, may not be a lot of output, but we’d need to know exactly how many Wh of lithium you’ll install @ 24V and what your usage patterns are. Do you go from dock to dock? Do you spend weeks on end at anchor? Are you in equatorial or northern latitudes? That significantly impacts how much you can get from your solar power. For example, in WA and BC, 1000 W of solar will yield about 250Amp-Hrs per day from May to August, but a lot less the remainder of the year (as little at 50 Ah in the winter). In the Carribean, you’ll get less daytime hrs, but more even output between the seasons.
Ideally, if all your heavy loads are on 24 V (fridge, anchor windlass, inverters, autopilot, bow thruster, etc…), you could have a large 24VDC bank and a small 12VDC bank for “essential” systems that draw littler power (LED lights interior and navigation, VHF radio, instruments, 12V outlets). This small battery could be charged from a DC-DC charger, while your alternator charges your 24V house bank. Another DC-DC charger would also charge the starter battery.
Depending on how you wire the DC-DC chargers, they can run all the time or only when there is a charge source into the main 24V house bank.
Do you have a single very large solar panel? If not, the system would benefit from having a separate MPPT charger for each solar panel, to minimize any effects of shading. This also provides system redundancy.
What will the output of the alternator be connected to? Ideally, you would have an “always on” 24 V, to which all charging sources are connected (alternator, MPPT, inverter/charger). This means you would not need the XS 1400 to charge the 24V bank, but you would use it to charge the 12V essential systems bank and another to charge the 12V starter battery.
Another way to power the 12V systems, which is simpler but provides a little less systems redundancy/failover protection, is to use a 24V to 12V converter, so those loads would always come off the large 24V house bank.
Another good upgrade if you’re getting rid of the propane stove is a 3 in 1 microwave, which does microwave, convection and air fryer, that way, you don’t loose anything by removing the oven!
Balmar 618 is a fairly old product. I’d suggest something like a Wakespeed or an Arco Zeus which provide ease of programming, advanced features and integration with the Victron ecosystem.
I would strongly advise on getting some professional advice early on, to avoid costly mistakes and rework ! Have fun.