My Samsung Note 4 will work until about 20% battery life. At that point I usually receive the low battery warning but then it just dies almost immediately after notification with hardly any continued battery drain. This has been a progressive issue and I believe it is linked to battery health.
I've had it die at even higher battery % at about 30% but that is really rare.
I have owned my Samsung Note 4 for about a year now with the original battery as its only used battery. I preordered it and received it on release day. The battery has gone through many cycles. I estimate on average 1 to 2 full drains per day everyday for about a year now. At this point I tend to just leave it plugged in while I'm near an outlet continuously now.
I charge it with and without the fast charger. When not in bed I use the fast charger. When I'm sleeping I use a standard basic charger.
I'm currently using an app called Battery Monitor Widget to monitor my mAh with this battery. I also just received a second battery that I will test too.
Does anyone know what could cause my phone to die at around 20%? Is it battery health?