I know this question has been asked quite a few times on this site. The closest one i could find is: make-9v-ups-for-router-with-tp4056-and-mt3608.
While there are UPS systems designed for routers, in my country, they literally cost more than the router. I am just trying to see if I can learn anything from trying to put together my own UPS system.
Problem: I have a 12V 1.5A Nokia router. During our daily power cuts (my apartment backup kicks-in in about 5s to at most 1min) my router decides to give up on life and doom me to the internet black hole.
I just need to have a UPS system to ensure uninterrupted internet during the switch over from mains to apartment backup.
This is what I have so far (with my amateur reasoning of it):
My router comes with a 12V 1.5A DC adapter that I am planning to replace with a 12V 2A DC adapter. Connected to this would be a 2S1P Li-Ion 18650 batteries (Samsung make) that will be charged through a 2S BMS board (TP5100). The output from this backup has to go through a XL6009E1 to meet the 12V supply required by my router.
I plan to setup the Li-Ion batteries in series using Nickel strips and with glass fuses rated at 2A each. I wanted the backup to kick in only once the mains went out and so I have got a IRF9520 P-MOSFET along with 1N5408 diodes (the only ones I could get my hands on) for switching the power supply and for reverse voltage protection.
Along with these, I got a couple of pull down resistors (100K), capacitors (4.7μF 25V Electrolytic capacitors) and a heat sink for a TO 220 package.
Will this circuit work to charge my batteries and provide power to the router and then successfully switch to backup for those precious few seconds when the mains cut out?
I just want to make sure I don't burn the house down or something.