I've been trying to figure something out for a while, and have experience with digital systems (logic gates, flip-flops, etc.), but not necessarily "real" systems (with Zener diodes, etc.) so here goes the preamble...
Looking at other posts here, I'm not going to try to build anything. What I want is something to run my 19V Router (1.75A max based on the wall wart) + 5V 2A ATA (2A, again by the wall wart) during a power failure. But I want hours of runtime, and not minutes, so an off-the-shelf UPS is right out (without any modifications, AC->DC->AC->DC conversions).
Reading a response on this post, it seems like the best idea is to hook up a charger right to an AGM battery (or other lead acid). So then I want to get a good charger to maintain the life of my battery, so I came across a charge controller for solar panels, which is great, because according to this thread, I can attach a 120VAC -> 30VDC transformer to a 24V charge controller, the controller to a 24V AGM, and the battery terminals to a few buck regulators for the 19VDC and 5VDC, and voila! Simple DC UPS... I think.
Now here's the question(s): 1) Should I worry about the charging profile (PWM and MPPT) affecting the buck regulators / the output to the router & ATA? Or will the presence of the battery help "buffer" the fluctuations to keep the steady ~24VDC? 2) This is one I'm throwing out there to see what people have to say about it: I notice that the charge controller has a "load" output (link added to explain what I'm referring to, not necessarily for buying advice). Could I use this instead of connecting directly to the batteries? I doubt I'll need to use the LVD function, but I don't know how it'll work (0 switchover time, etc.). This post makes it look like it doesn't work that way looking at the relay, but I don't know.
Thanks in advance!