Samsung Galaxy won't charge to 100%? Battery protection explained

howtosimply.com/guides/samsung-galaxy-won-t-charge-to-100-battery-protection-explained/ · Checked October 2026 · Samsung Galaxy A57 5G (One UI 8.5, Android 16) and Samsung Galaxy A57 (One UI 9, Android 17 (build A576BXXU6BZIE))

4 of 6 steps with real screenshots · 3 official sources below

Device

Android

Shown on

Samsung Galaxy A57 5G (SM-A576B), One UI 8.5, Android 16, Samsung Galaxy A57 (SM-A576B), One UI 9, Android 17 (build A576BXXU6BZIE)

App

Settings

Path

Settings › Battery

Real screenshots

4 of 6 steps

Our phone

Shown on Galaxy A57, One UI 8.5

Checked

October 2026

Sources

3 official, linked below

Step by step

1. 

   Open Battery protection

   Open Settings, Battery and scroll down to Battery protection.

   Watch these steps Done

2. 

   See whether it is on

   Settings, Battery. The switch next to Battery protection shows whether it is on, and the word underneath shows the mode. Ours was on, with Basic. If it is off, the limits below do not apply and the cause is elsewhere (see the last step).

   Done

3. 

   Stuck between 95% and 99%? That is Basic

   With Basic, charging stops at 100% and only starts again when the battery drops to 95%. Unplugging at 96% after a long charge is normal.

   Done

4. 

   Stopped at 80%, 85% or 90%? That is Maximum

   Maximum stops charging at the level you chose with its slider. Ours offered 80%, 85%, 90% and 95%. Pick Basic or switch Battery protection off to charge further.

   Done

5. Only 80% in the morning? Check Sleep time protection

   It stops at 80% while you are asleep and finishes to 100% just before you wake up. Samsung says it learns your sleep pattern over about 2 weeks and may not work if your sleep is irregular. If your mornings vary, choose Basic or Maximum instead.

   Done

6. Still not reaching 100% with it off

   Try another wall charger and cable, clean fluff out of the port, and check the battery health. An old battery can also stop short.

   Done

Watch these steps

If you do not see this option

• There is no Basic or Maximum Samsung's One UI 6.1 page says that below One UI 6.1 the only choice is to limit charging to 85%. Source: Galaxy Battery protection feature in One UI 6.1
• You see Adaptive too Samsung says Adaptive charges to 100% about an hour before you usually wake, and might not work well if your sleep times are irregular. Source: Galaxy Battery protection feature in One UI 6.1

If this does not work

• Basic is on, but it shows 100% for hours Samsung says this is normal: at 100% the phone runs on the charger's power instead of the battery, so the level can stay there. Source: Protect your battery for longer and safer use (Battery protection)
• Maximum is at 80%, but it shows 78% Samsung says that with Maximum, charging starts again when the level drops about 2% below the limit, so a small dip is normal. Source: Protect your battery for longer and safer use (Battery protection)
• Sleep time protection does nothing Samsung says it needs about 2 weeks to learn your sleep pattern and needs Customisation Service turned on. In multi-user mode, or without that consent, it can switch itself to Basic. Source: Protect your battery for longer and safer use (Battery protection)

About this guide

Samsung added these limits to slow battery wear. They look like a charging fault, but the phone is following a setting. Battery protection was on on our phone, set to Basic.

We selected Maximum for one picture and set it back to Basic. Step 4 is from the same phone after its One UI 9 update (Android 17).

Good to know

Samsung's older One UI 6.1 page calls a similar option Adaptive. Samsung says menu names vary by device and software version.

To set a limit on purpose: how to limit charging to 80% on a Samsung Galaxy phone.

Check the battery itself: how to check battery health on a Samsung Galaxy phone.

In short: Settings, Battery, Battery protection: Basic resumes at 95%, Maximum stops at your level, Sleep time protection holds 80% overnight.

📷 See real photos from the Galaxy A57 in our Camera Lab, next to 10 other phones.