Knowing the inherent inefficiencies in converting back and forth between DC/AC, I'm looking at a method to stretch my backup batteries for one specific use case. Using a standard UPS to drive my main network devices that are predominantly native 12vdc powered via wall warts. The big UPS says I'll get an hour of runtime. But that includes tons of wasted electrons due to heat in the conversion process.
I know I can get HOURS (if not days) out of native 12vdc batteries to power devices that also have 12vdc inputs. And UPS units (at least small ones) all use 12vdc sealed batteries. But typically there is no way to directly tap that battery. You have to grab the voltage on the other side of the inverter after it has wasted a ton of electrons due to heat and converted it to 120vac, which the brick then converts it back down to 12vdc. So I want to cut out the middle man.
So if I wanted to run a handful of 12vdc devices off a 12vdc battery bank, what would I need to constantly keep those batteries topped off from utility voltage? We arent talking huge loads. Just a router, cable modem, AP, etc.
I know I can get HOURS (if not days) out of native 12vdc batteries to power devices that also have 12vdc inputs. And UPS units (at least small ones) all use 12vdc sealed batteries. But typically there is no way to directly tap that battery. You have to grab the voltage on the other side of the inverter after it has wasted a ton of electrons due to heat and converted it to 120vac, which the brick then converts it back down to 12vdc. So I want to cut out the middle man.
So if I wanted to run a handful of 12vdc devices off a 12vdc battery bank, what would I need to constantly keep those batteries topped off from utility voltage? We arent talking huge loads. Just a router, cable modem, AP, etc.
