Just to add to the above. For instance, not only smaller wiring with 24 V but you can double the amp input to your charge controller by running to a 24 V pack rather than 24. I was building up a lot of heat in my 60 amp charge controiller
Researching and going to build an RV Solar system.
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Another potential setup which I ended up with not by design but evolution is that you could have a smaller 100 ah or 50 ah 12-volt pack to handle and sudden high needs in your 12 volts system (electric landing gear) and then a large 24 volt pack. I feed the 12 volt pack with the Victron dc to dc I referenced above (you can set the voltage output). Since you are not feeding a 12 volt inverter you don't need the large wiring and you can get then run a 24 volt inverter and your 24 v from charge controller to battery.
Could be intersting but have a cpap that drags a good amt of current at 12 volts but the DC adapter may be capable of running off a 24 volt cig lighter connection. So many alternatives makes one's head hurt
My scheme can also work for him if he doesn't need to pull more than about 450W continuous from the Alternator. This one: https://diysolarforum.com/threads/r...rs-of-mppt-charge-solar-in-the-trailer.20730/
It switches into charging on-the-fly via a dashboard switch, which I only flick on when I'm already driving with relatively high RPMs. Saves the Alternator (mine is not "huge", and goes right through the Bargman cable (at ~13A, 36.0 "boosted" Voltage on the "Trailer Battery Charge" wire). The Trailer switches to use input to an MPPT controller automatically, disconnecting any "Real" PV panel array which is normally connected into that MPPT. The MPPT must be the limiting factor, putting out no more than about 30A (at 14.5V) into an LFP battery string at low SOC.
This would call for a split configuration - maybe "300W - 400W" of rated panels on the switching MPPT, and the rest of the panels going through a dedicagte bigger MPPT (capable of perhaps 40A maximum into "12v"). My scheme could certainly support a "24 Volt" battery bank as well, (the 36 Volt "fake Panel" is well above that too), as long as the switching MPPT was limited to only 15A maximum charging current.
One major brand of CPAP, ResMed, uses 24V on the main "power connection, and they have a funky little "test to be sure that only our power supply is being used" trick involving a "sweep" of a 3.3V test wire with a defined resistor. I found it easy and fun to build my own power supply, ~13V into Resmed, mostly because I was a bit angry that they but in the silly test circuit -- and I wanted to prove that I could "fake it" with only a few cheap parts. I'm sure that ResMed accepts at least 25.6V on the main power line, but you might need to use their "12v" power adapter (bigger and more complex) to stay under that value on a "24 Volt" LFP system (Which might be getting charged at more than 28 volts).
With a "24V" LFP battery system, you would need a regulating "buck" converter to drop the voltage to less than 25V - and then you would use my little "trick resmed" circuit to do the 3.3.Volt job, and simply go straight through on the buck converter output to the Resmed. The box which I built takes 10-15 volts input, does a BOOST conversion to 24.0 regulated output, and then branches through a buck converter to offer the same "trick ResMed wire" on output.
Although mine does not, I suspect that Resmed's own "12-VDC" converter can handle both "buck" and "boost" from a more arbitrary input DC Voltage. It's certainly got a ton more parts in it, and it's a lot more expensive. But, if you're willing to reward Resmed for creating the danged "only ResMed power supplies" circuit, and it CAN accept both input voltage ranges, then that's probably your best route. My simple design is pinned as a "12V" Boost converter for 14.6V and less. It's here, and I am AKA "the snoring man" on that other board.