There are a lot of recommendations when it comes to keeping your battery healthy and for the most part they are all similar, differing by a few percent here and there. So tismydroid recommended 30% to 80%. I've seen lows recommended as low as 10% to 15% and truthfully I don't think the low matters all that much as long as you heed tismydroid's advice and avoid letting it go to zero or power itself off. It's not good for the battery but it is also not good for the device. It is actually terrible for the device, just saying. Anyway as for the high, it is usually around 80%, Samsung recently added a battery protection setting in One UI that stops the charging at 85%. I personally fully charge on work days and use the 85% protection charging on my days off. I could probably use battery protection all of the time and just never fully charge because I'm never very far from a charger but there's the flipside to all of this battery care stuff, which is more batteries without much fuss are going to last two or three years before they have any real or noticeable degradation. If you are one to keep a device for years and years it might pay to be a little extra about battery care. If on the other hand you are one to replace devices on a regular basis like every two or three years the benefit is probably going to be nominal.