topic S20 ultra battery draining and won't charge while switched on in Galaxy Note Series

S20 ultra battery draining and won't charge while switched on

Liz12321 — Thu, 26 Jun 2025 11:21:03 GMT

Hi,

I have a battery draining issue with my Samsung Galaxy Note20 Ultra 5G.

This has happened suddenly over the last few weeks. (I keep reading about a software update which causes the battery to drain...I don't know if this is the problem. My last update (UI version 5.1) was done on the 7th of May. It was a security patch dated 1st April.

I used to be able to charge my phone once a day. Then I noticed a few weeks ago that I was having to charge it more often. Earlier this week, I noticed that after it got to about 50%, it drained really quickly. I plugged in the charger and it would charge ok while still switched on.

Now, since yesterday, I can't charge it while it is switched on. I have to switch it off, plug in the charger and then switch it on.

This is what happened last night and this morning. I switched it off, charged it to 100% last night. This morning, I started it and the battery was at 78%. That was dropping before my eyes. It got to 50% and plugged in my charger but it wouldn't work. Switched it off, plugged in the charger and the battery registered at 11% and charged.

I've checked for apps that use a lot of battery and everything seems fine. In settings, my battery shows as being good. At 100% it shows that I should have 10 hours. But in reality, I've possibly not even got one hour. I've lowered my brightness and I don't think I have any background apps running.

Any ideas what the problem is?

Edit - Since writing this post, I've run the diagnostics on the phone, where you need to sign in to Samsung. It actually says the battery is weak. So I presume I need a new battery. I have organised that. Hopefully it will be fine afterwards.

Re: S20 ultra battery draining and won't charge while switched on

MNas04 — Thu, 26 Jun 2025 11:11:23 GMT

How long have you had the phone for

Re: S20 ultra battery draining and won't charge while switched on

Liz12321 — Thu, 26 Jun 2025 11:19:57 GMT

I've had it since the start of 2021.

Since writing this post, I've run the diagnostics on the phone, where you need to sign in to Samsung. It actually says the battery is weak. So I presume I need a new battery. I have organised that. Hopefully it will be fine afterwards.

Re: Re: S20 ultra battery draining and won't charge while switched on

MNas04 — Thu, 26 Jun 2025 11:43:01 GMT

Okay. Hope it goes well. Any issues you can always report back

Re: S20 ultra battery draining and won't charge while switched on

JAMES4578 — Thu, 26 Jun 2025 13:50:57 GMT

Hi @Liz1321 obviously your decision if you wish to change Battery. However just pointing that the S20 is no longer supported, I.e. will not longer receive security updates which increases vulnerability. https://www.sammobile.com/news/its-time-to-say-goodbye-to-the-galaxy-s20-as-support-ends/

Therefore you may wish to consider one of the Modern Devices if in a position to do so. A variety of options detailed here https://www.androidauthority.com/best-samsung-phones-771831/ There is also the Edge https://www.samsung.com/uk/smartphones/galaxy-s25-edge/

Re: S20 ultra battery draining and won't charge while switched on

Liz12321 — Thu, 26 Jun 2025 14:20:07 GMT

Thanks James. The cost of replacing the battery is easier on my purse right now.

Isn't it a wee bit annoying that they stop doing security updates when a phone isn't even 5 years old?

Re: Re: S20 ultra battery draining and won't charge while switched on

JAMES4578 — Thu, 26 Jun 2025 15:01:28 GMT

Ok, 7 cycles of security patches are provided for modern premium Devices (from 2024 onwards) unfortunately not the same support for older Devices).

Re: Re: S20 ultra battery draining and won't charge while switched on

Liz12321 — Thu, 26 Jun 2025 15:08:33 GMT

Thank you for the info

Re: S20 ultra battery draining and won't charge while switched on

jonno1607 — Thu, 26 Jun 2025 17:01:20 GMT

Sadly the battery is wearing down due to its age and use.When you have new battery fitted set the max charge to 80%.after about a month or so,set 85% this will give longer battery life.