Beginner - solar/alternator excess power water tank heating question

[Vision.Urban.Reed]

I am reading related posts on this concept as I post this, as I clarify my understanding, I will remove this beginner post. I am mostly wondering about using the hot water reservoir as an accumulator of sorts, or if I should move the cold line accumulator back in the chain to after the pump and before the split. I am using a victron MPPT 12v 30 amp unit, with 460w solar, and a victron orion 12/12/18 charger

 

[DThames]

An AC thermostat switch should not be used for DC. It can weld shut. You might get by with it at only 12v but I would use some other way to switch DC to a heater.

You will need a control system or a charging system that has switching for transferring load after the battery is charged.....if that is your only concern about putting the power the water heater. From what I understand, you also want to heat the water when you want a shower, which can't depend on "excess" from solar. I have no RV experience, but heating water takes a lot of energy. Depending on tank size, you might need hours to heat from solar, depending on what panels you have connected.

 

[Vision.Urban.Reed]

An AC thermostat switch should not be used for DC. It can weld shut. You might get by with it at only 12v but I would use some other way to switch DC to a heater.

You will need a control system or a charging system that has switching for transferring load after the battery is charged.....if that is your only concern about putting the power the water heater. From what I understand, you also want to heat the water when you want a shower, which can't depend on "excess" from solar. I have no RV experience, but heating water takes a lot of energy. Depending on tank size, you might need hours to heat from solar, depending on what panels you have connected.

Thank you, I shall heed this 230v vs 12v switch advice.
As to the automatic transferring of excess energy to different destinations, there is a built in relay on this victron battery management device that I am learning about right now, I am figuring out a way to set it up right now. I am thinking this: once a certain state of charge or voltage has been reached on the LiFePo4 battery, I would figure out a solution to switch over to heating the water tank.

That still leaves your point about generating hot water for showers on demand. Great point. I guess it's time to go down another rabbit hole