Batteries are Cheap, Backup power is expensive

Hey @phildebrandt - Make sure you compare usable power.  LiFePO4 batteries can be used for almost 100% of their amp hours (Ah) while lead acid 50%. 

If you have the room, I can see lead acid beating out LiFePO4 for $/usable watt hours. 

Great point @erik_squires ! I hadn’t thought about that limitation when I did the calculation. That was for an old EV Restauration project (a 1910 Baker Electric) and I ended up with a stack of golf cart batteries that nicely took the place of the original Edison batteries.  I would need to look at it again. 
 

@tomrk The point about dirty generator power is very real. I think going forward I would only use an inverter generator, and I’m looking into running my generator output through one of my solar inverters (convert to 480 V DC and then let the inverter create clean 120/240V AC)

Now, inverters pollute the power with their switching frequency, typically just outside the “audible range”, at 25kHz give or take. That’s why I mentioned that I have isolation transformers to deal with that before it reaches my Audio gear

OP

I have a Renogy 1000 with 2x car sealed battery. I live in California so there are not much power outages but if the city power blew up the tranny during hot months, well there it is. I manually switch over my router, switches and Wi-Fi over to the Renogy and some lights and Fan. It works for about 6 hours straight for me experience

with today's tech, see how a Solar panel can charge your batteries and if large enough, power up your home data center

@joeycastillo  - I lived in California a long time.  The power may not go out but it's not always right... :D 

That's kind of what I'm talking about, but in my case I'm going to leave  the inverter in 24/7.  Inverter is sized at 500W, and I'll use 50W.  Batteries will stay on a charger 24/7.  No transfer times.  At most in an emergency when my Ecoflow isn't working or doing other duties It may draw 110W.  I'm starting off cheap.  I had a 500W inverter for the car/emergencies already. It was $70 or something.  I'm going to try it out for now and see how it goes.  If I win the lottery or something I'll consider something significantly larger. 

By my calculations, with 2x 100Ah batteries I should get about 40 hours of run time for Internet alone.  

@erik_squires 

I now understand how you're planning to wire this setup of yours. I think it will work. Mine is more manual. I use the Inverter when I want to be standalone. Then after nearly draining the battery, I then connect the batteries to a charger to fully charge it back. 

So, in your case, you want 24x7 power from the Inverter. in that case, you need a Charger sized to keep the battery "charge" at the same time feeding your devices.

you need to research how to determine this power rating necessary to accomplish this. or crudely, i will attach an amp meter between the battery and inverter when you have all your devices plug in and determine the amps drawn. then choose charger based on that. (give it some headroom)