Use 18650 battery for 4g router

Hello everybody,

I have an old huawei r215 4g router with the battery almost dead, the original battery has three pins (you can see it here and here ), I found on youtube a tutorial how to build a "fake battery" with a capacitor and two resistors (here DIY Simple Dummy Baterai (Fake Baterai) | DIY. - YouTube ), but I'd like to use a 18650 battery: it has the same voltage, but i cannot understand how to connect it to the central pin, which I think should control battery status, using a resistor as shown in the tutorial could work? can anyone help me?

Thanks a lot

Simple enough.
Do the fake battery thing from the video, then buy an 18650 to USB power supply since it's already ready to go and plug it into the micro-USB port.
Fast and easy.