How to calculate the battery life of the router?

Question

Electronics

There is ...
1) a Wi-Fi router,
2) a 12 volt battery,
3) a stabilizer to make 12 volts 9 volts.
Only 3 elements.
If you connect them, how long will the router work when fully charged from the 1st battery?
(I can buy two batteries too)
I care about the days, I was told 20 days from the 1st battery. It's true ? Is it possible?
I need a Wi-Fi router to work for 1 month on battery power, it will work longer, even better.
WiFi router.

Battery.

Stabilizer.

I am not an electronics engineer, but it seems to me that this is a simple question. Thank you for attention.

Answer 1

Firstly, the converter, most likely, is not needed - there is a router in the bowels of the router, but this is not accurate.
Secondly, the router wants to eat 9 [V] * 0.6 [A] \u003d 5.4 [Watts]
If we assume that the converter is not complete junk, we will take its efficiency as 0.9
5.4 W / 0.9 \u003d 6 W
Why, at 12 volts, you need to give current 6[W]/12[V]=0.5A.
Our battery at a current of 1 ampere lives 9 hours, so from 0.5 amperes it will live 18 hours. So sorry, for it to work for a month, you need a battery from the tank.

Answer 2

I need a Wi-Fi router to work 1 month on battery, it will work longer, even better

Wow.
See. The battery can deliver 9 amps per hour. Your router sucks 0.6. We divide 9 by 0.6, we get 15 theoretical hours of work.

Answer 3

9 / 0.6 = 15 часов