I’m tired of buying a new 12 V battery every 1-2 years. I have about 4 small (rated ~ 300 W [not VA]) UPSes with 7 Ah, 12 V, maintenance free batteries.
I’m thinking about replacing them with one, powerful unit. But the more powerful the unit, the more it costs - non-linear.
Do you have experience with some DIY solutions? Like 12V DC to 230V AC inverter, battery charger, some UPS controller (simple relay?)?
Or maybe you have some other idea that is cheap(ish)?
You’d want to use a deep cycle (sometimes labeled “marine”) battery, not a car battery. Car batteries can put out a shit ton of power for a very short time but their total capacity is pretty low.
Also you still want AGM, Gel or something else sealed like that. You don’t want a Flooded Lead Acid battery charging/being trickle charged inside your house.
Op could also swap to LiFePO4