We have a small 120V low-current hot tub that works great plugged into a standard household outlet. I would like to supplement the grid power with solar power.
On hand, I have four 250W panels and a 300Ah LiFeBlue battery. It would be simple enough to add an inverter and solar charge controller and then power the hot tub from the battery.
But, I'd like to set this up so it can also use grid power when the battery is too low. The way I see this working is that the hot tube first uses up the battery and then, if necessary, switches to grid power until the battery can be charged again.
With the current Prime-Day sales on EcoFlow power banks, it's tempting to just buy an all-in-one and plug everything into it. But I haven't been able to verify that I can set up a battery-priority output. It's sort of the opposite of the typical emergency power bank that uses grid power normally and then switches to battery power in an emergency. I want to use solar/battery power normally and then switch to grid power in an "emergency." (If there's a power bank that is already set up to do this, I wouldn't mind spending the money for a plug-n-play solution. I also have lots of cables, lugs, etc. and could easily assemble an all-in-one, if only I knew how to transfer between my house's circuit and the solar/battery circuit.)
I'm happy to consider all ideas. But seeing as my long-term plan is to also add passive solar water heating, and because we live in a warm climate and the water doesn't have to be kept very hot, I'm not concerned with the amount of energy required. I just want to add a bit of solar-generated power to the plug-in system that's already in place.
Thanks in advance for any help with this.
On hand, I have four 250W panels and a 300Ah LiFeBlue battery. It would be simple enough to add an inverter and solar charge controller and then power the hot tub from the battery.
But, I'd like to set this up so it can also use grid power when the battery is too low. The way I see this working is that the hot tube first uses up the battery and then, if necessary, switches to grid power until the battery can be charged again.
With the current Prime-Day sales on EcoFlow power banks, it's tempting to just buy an all-in-one and plug everything into it. But I haven't been able to verify that I can set up a battery-priority output. It's sort of the opposite of the typical emergency power bank that uses grid power normally and then switches to battery power in an emergency. I want to use solar/battery power normally and then switch to grid power in an "emergency." (If there's a power bank that is already set up to do this, I wouldn't mind spending the money for a plug-n-play solution. I also have lots of cables, lugs, etc. and could easily assemble an all-in-one, if only I knew how to transfer between my house's circuit and the solar/battery circuit.)
I'm happy to consider all ideas. But seeing as my long-term plan is to also add passive solar water heating, and because we live in a warm climate and the water doesn't have to be kept very hot, I'm not concerned with the amount of energy required. I just want to add a bit of solar-generated power to the plug-in system that's already in place.
Thanks in advance for any help with this.
