krby
Solar Enthusiast
I was thinking about putting together a UPS-type thing based mostly on gear I happen to have already and I wanted feedback on a few things. My load is some home networking gear in a rack. It will be no more than ~220W of AC, probably more like 100W on average.
In a basic solar setup, you have panels providing DC to a solar controller, then the battery and inverter hanging off the solar controller. In effect, the solar controller is keeping the battery charged and then providing extra current to the inverter. So, let's say I replace the solar panels with a 24V DC power supply that can handle the max power of the load. I think what I've got now is a double conversion UPS right? From other projects, I already have a PSU, a battery or two I could use, and an inverter.
Do I have this right? Assuming the PSU and solar controller can support 250W, will this work? It's like a solar setup where it never gets dark.
Followup questions:
In a basic solar setup, you have panels providing DC to a solar controller, then the battery and inverter hanging off the solar controller. In effect, the solar controller is keeping the battery charged and then providing extra current to the inverter. So, let's say I replace the solar panels with a 24V DC power supply that can handle the max power of the load. I think what I've got now is a double conversion UPS right? From other projects, I already have a PSU, a battery or two I could use, and an inverter.
Do I have this right? Assuming the PSU and solar controller can support 250W, will this work? It's like a solar setup where it never gets dark.
Followup questions:
- Since I'm going to have steady source of DC, do I need a solar controller? Can I just use a battery charger? I've looked at a few, and I've noticed that 20-30A battery chargers seem more expensive than equivalent solar controllers and from what I have read I'm not sure they'll still supply 20A if they're just in float or trickle mode.
- If you all tell me I need a solar controller, I think I can just get PWM, no need for MPPT if the input is a steady 24V, right?
- Can I do this with a LiFePO4 battery? My instinct is I can't because unlike a real solar setup, in this case, the battery will be charged nearly all of the time. From what I know, an SLA will handle being full for months or years on end better than a LFE. I wouldn't consider the cost of a LFE, but I have one already hand from a HAM radio project.
- As I understand it, the load and battery are just wired in parallel, but with some disconnect logic. Right? Are their separate terminals to do low voltage cutoff and similar protection?