Is it harmful to use the phone as a modem?

Question

Mobile devices

You have to use your smartphone as a modem. Battery 3500 mAh, with this use sits down quickly. I do not connect to yuzb, only as a router. Is this bad for the battery?

Answer 1

Well, it's kind of harmful, of course, but that's what it's designed for. The battery is a consumable.
Connect it to a USB cable, what's the problem?

Answer 2

It is possible, but if you use the modem permanently - minus the battery.
Use some old phone