iPhone uses battery or charging cable when battery is 100%?

[PEVO]

Simple question: if the battery is full (100%) and I keep my phone connected to the cable, iPhone will use the battery or directly the power of the cable?

I'm currently using the phone as a hotspot to my PC via cable, so the phone's battery stays at 100% and I can use the hotspot. But I don't know if in this way I'm ruining the phone's battery or not.

 

[Bichon]

It will run off the battery, but the charging circuitry will kick in frequently and charge it back to 100%. This usage pattern isn't great for long term battery health, especially if you are in a low signal area and the phone starts getting warm. Very common for those that leave their phone (or laptop for that matter) plugged in constantly to eventually have problems with the battery swelling.

 

[PEVO]

So there is no way to prevent charging the phone’s battery when is already at 100%?
There are so many different opinions about this topic online

 

[Kottu]

When you use phone as hotspot, depending on your usage, iPhone will get warm. If your phone is not fully charged so it’s charging at the same time, phone can be really hot. Warm battery deteriorates faster. What I have noticed that if I use my iPhone tethering via USB instead of wireless, iPhone doesn’t get warm much.

 

[Helmsley]

So there is no way to prevent charging the phone’s battery when is already at 100%?
There are so many different opinions about this topic online

iPhone does that already. But, as a previous poster said, it will keep topping itself up as the charge level drops.

 

[AhmetRyzen]

It uses mains electricity. I tested and approved