how long I have to charge S9+ for using the first time

[Android Central Question]

how long I have to charge S9+ for using the first time

 

[belodion]

I don’t think there’s any ‘have to’ about it. I charge to 100% then leave it charging for another fifteen minutes or do, but that’s just me.

 

[Mooncatt]

Li-ion batteries don't need any break in and you can start using it straight away. Charging above 80% can also put it under additional stress that can degrade it quicker (the same for draining below 40%).

If you still want to charge to full for whatever reason, 100% on the gauge may not be completely full. Manufactures can calibrate it to show 100% at a lower capacity. To make sure it is full, you'll want to leave it on up to an additional hour or so. You can also install a battery monitoring app. As the battery gets above 75%, you'll see the voltage hold steady and the current starts to decrease. When it gets to 100mA, that's typically when charging cuts off and it's truly full.

I prefer this app for battery monitoring, because it gives the most fine detailed info.

https://play.google.com/store/apps/details?id=ccc71.bmw