I agree with Paul. My battery is down to 45% by 9pm. This battery life is way decent than my s10 plus. Especially being that I'm off the charger by 3 and at work at that time. You may need to check those apps.
At the beginning of the opening of your S20+, the battery usage time may be short because of app update, restoring of your data from google or samsung server.
You can check it again after using it for about a week.
I am having the same issue brand new s20 , waited for 3 days to learn usage patterns
But battery draining very quickly need to charge twice a day
What are the solutions ?
Am already in medium power saver mode and 60hz with Fhd
I just got brand new S20 plus Exynos version yesterday, did all the transfers and took to work with full charge full this morning but in 2 hours of light usage it was down to 60%. Turned screen resolution down, location settings and always-on display off, Dark mode on and hardly used the device through the day to end up with 20% by 8pm. I'm sure if I had to run GPS or anything like that, I'd be out of power by noon. Disappointed start.