A Note20 Ultra is six years old, so most fast drain is the battery, but the forums show two other causes. On One UI 5.1 owners saw Google Play Services draining 10 to 15 percent of a charge in a cycle after the September security patch, and several Exynos-version owners reported heavy drain even after a battery replacement. Check Settings, Battery for Google Play services and for one app leading, then run the Samsung Members battery test. Samsung's US list shows $269 for a Note20 Ultra module repair with a new battery.
Differential
Likely causes of “Samsung Galaxy Note20 family battery drains too quickly”, and how to tell them apart
- 1
Google Play Services looping
What separates it Settings, Battery lists Google Play services at or near the top
How to confirm Owners on One UI 5.1 saw it take 10 to 15 percent of a cycle; clear its cache and update it
- 2
A six-year-old battery
What separates it The phone dies at 30 percent and runs warm
How to confirm Samsung Members' battery test reports the cell
- 3
The Exynos chip
What separates it Drain continues after a new battery on an Exynos unit
How to confirm Owners on XDA report heavy drain on Exynos versions; Wikipedia lists the Exynos 990 for Europe and Asia Pacific
- 4
A swelling cell
What separates it The back lifts or the screen gaps
How to confirm Stop charging and go to a repair center
Before you touch a setting
Record this first — changing settings destroys the evidence
- The Samsung Members battery test result
- Whether the phone has the Exynos or Snapdragon chip
- Whether the back or screen has lifted
Try in this order
0 of 3 completedRead the battery list
ReversibleOpen Settings, Battery. Note whether Google Play services leads.
Clear Play Services' cache
ReversibleOpen Settings, Apps, Google Play services, Storage, Clear cache, then restart.
Get a repair quote
ReversibleAsk for a battery replacement price.
Model-specific
What is true of this model and not of its siblings
- Battery
- 4,500 mAh with wired charging to 25W, Qi wireless and 4.5W reverse charging, per Wikipedia.
- Other models this page answers
- These steps also fit the Galaxy Note20.
Stop boundary
When this stops being a self-service repair
- !If the back lifts or the screen gaps, stop charging and go the same day
- !If the battery test reports a fault, get a quote; a new battery did not cure one Exynos owner's drain
Evidence ledger
Sources behind this answer
Owners on Google Play Services draining the battery.
An owner with drain after a new battery.
Exynos owners' drain reports.
Note20 and Note20 Ultra battery, charging, chip by region, storage and microSD, Wi-Fi, display, glass, frame and end of software support.
Exact questions
Common questions
Why is Google Play Services draining my Note20 Ultra?+
Owners on One UI 5.1 reported it using 10 to 15 percent of a charge cycle after the September security patch; clearing its cache and updating it was the first step.
Will a new battery fix the drain?+
Often, but an Exynos owner in Samsung's EU forum reported heavy drain even after replacing it.
How big is the Note20 Ultra battery?+
Wikipedia lists 4,500 mAh with wired charging up to 25W, Qi wireless and 4.5W reverse charging.
Is the Exynos Note20 Ultra worse for battery?+
Owners on XDA and in Samsung's EU forum report heavy drain on Exynos versions, one even after fitting a new battery. Wikipedia lists the Exynos 990 for Europe and Asia Pacific and the Snapdragon 865+ for North America.
Does Samsung still update the Note20 Ultra?+
Wikipedia's Note20 article records the end of software support; a phone without patches is one more reason to replace a drained battery with a newer phone.
How do I start the Samsung Members battery test?+
Open Samsung Members, tap Support, Phone diagnostics and choose Battery. It reports whether the cell passes or needs replacing.
Can the S Pen drain the Note20 Ultra's battery?+
The S Pen has its own small battery and does not noticeably drain the phone; Air actions use Bluetooth, which can add a little drain when active.
Should I replace the Note20 Ultra's battery or the phone?+
If the phone is out of updates and the battery is worn, compare the repair cost with a newer phone; a replacement battery gives a better experience at low cost.
How do I check the Note20 Ultra's battery health?+
Samsung Members' diagnostics include a battery check, and Battery and device care shows usage.
Does the 120 Hz screen drain the Note20 Ultra?+
Yes. A 60 Hz refresh rate saves power when you need the phone to last.