Overview of a miniature Wi-Fi router + make a pocket router out of it

Hello, I decided to review the miniatureWi-Fi router and my "work" with a sim device. So, it was ordered due to the fact that I live in a private house right now, and there is no wired Internet and no one will conduct it, the only option is 3G. MTC CDMA (Ukraine) was chosen as the operator, because there is no limit (albeit at 3.1Mbit / s).
Sobsno for the distribution of net from the modem this router was bought, that is, it is used around the clock on the distribution of the Internet. I enclose a photo of the router:


Well, regarding how it works, contrary toTo my fears, the router determined the Wetelecom WD-M200 modem from MTS independently and even selected the settings for the Internet itself. In general, there are no problems with it, it's lying to itself with a modem, but the Internet is distributing it. It’s enough to cover the entire private house, in spite of the thick walls (one of them is about a meter, and still pierces through it), but it is not enough in the yard, which is not surprising. I have not changed the firmware to OpenWRT or anything else so far, because the regular one is coping.
But I myself always wanted to get myself a portableRouter, so that it accepts 3G and distributes it from a bag / pocket to a smart tablet. Well, it seems like Wi-Fi eats less acb gadgets than GSM / 3G / 4G. In alish, such routers with a built-in battery cost from 20 bucks, (even closer to 27), I thought, I came up with a slightly cheaper solution. So, it was ordered like this unit, for which the 18650 battery was pulled out of a dead laptop battery, according to measurements, 1.2Ah still exists in them.

Next, I powered the router from a homemade“Power bank” and measured how much 1.2Ah is enough for such a router to distribute the Internet. The result turned out to be 2 hours 23 minutes, which, frankly, does not inspire joy from those ready-made routers with battery that sell on alish with battery 1.8Ah, that is, only 3-4 hours of work, as for me, for a portable Internet source not enough. In general, and subject to the purchase of a battery, the 18650 will be cheaper, because it will be released in a wounded 15 bucks for everything and with a normal battery, and not 1.8mAh.