How to charge Galaxy S9 battery?

After unboxing Galaxy S9 or S9+, you may want to charge Galaxy S9 battery so that you can start to set it up and use it.

When Samsung Galaxy S9 and S9+ left the factory, the battery is charged to about 50% of the capacity, which is sufficient for you to inspect the phone on the counter.

Because the only difference between Galaxy S9 battery and Galaxy S9+ battery is the size (capacity), charging Galaxy S9 battery is identical to that for Galaxy S9+. Therefore, we use Galaxy S9 to refer to both Galaxy S9 and S9+.

Two ways to charge Galaxy S9 battery

You can charge Galaxy S9 battery in two ways:

1. Using a USB cable (USB charging).
2. Using a wireless charging pad (wireless charging).

All Android phones now support USB charging. The charging port in most Android phones has been shifting from micro USB to USB-C.

Both Galaxy S9 and S9+ have a USB-C port for charging and data transfer.

In your Galaxy S9 box, you can find the wall charger and the USB cable to charge Galaxy S9 battery.

Galaxy S9 and S9+ also support wireless charging. Samsung has added the wireless charging to Galaxy phones since Galaxy S6.

You can put Galaxy S9 or S9+ on a wireless charging pad to charge the phone.

What is fast charging for Galaxy S9 and S9+?

A normal USB wall charger has a rated output current ranging from 500mA (0.5A/5V, 2.5W)  to 2000mA (2A/5V, 10W).

When using such USB wall chargers to charge Galaxy S9 and S9+, the charging voltage does not change. It is fixed at 5V. And Galaxy S9 and S9+ battery can take up to 2A current for this type of wall charger.

In addition to “normal” USB charging, Galaxy S9 and S9 also support fast charging when an adaptive wall charger (aka fast charger) is connected.

An adaptive wall charger can communicate with Galaxy S9 and S9+. Galaxy S9 and S9+ can then choose two charging modes:

1. Fast charging at 9v 1.67A (15W).
2. Standard charging at 5V up to 2A (10W).

The fast charging mode (mode 1) will be active only when:

• the battery level is less than about 60%; and
• the phone screen is turned off except always-on display; and
• the phone temperature is not too high.

As you can see, when you charge Galaxy S9 battery with fast charging, the charging speed can be 50% faster (for the first 60% of the battery).

To use Galaxy S9 fast charging, you must use a fast charger, which Samsung named as the adaptive charger.  Such an adaptive charger should have at least two output modes: 5V/2A, and 9v/1.67A.

Please note, some wall chargers can output 5V/3A. Galaxy S9 and S9+ will only draw up to 2A and will not use the full output capacity of such chargers.

What is wireless charging and fast wireless charging for Galaxy S9 and S9+?

Wireless charging is convenient. You just put Galaxy S9 or S9 on the wireless charging pad to charge Galaxy S9 and S9+.

But wireless charging is usually slow.  And it is always slower than the USB cable charging when the same wall charger is used.

The slowness in wireless charging is related to the way it works. Galaxy S9 and S9+ wireless charging rely on electromagnetic induction between coils in the charging pad and the coils inside the phone. The actual charging efficiency is usually less than 50%.

The standard wireless charging output is about or up to 5W (5V/1A).  Higher charging power may cause substantial heat on the charging coil and the charging pad due to the relatively low efficiency in wireless charging.

Galaxy S9 and S9+ support both Qi and PMA wireless charging standards. This means most wireless charging pads should work with Galaxy S9 and S9+. As iPhone 8 and iPhone X support Qi wireless charging standard, any wireless charging pads working with iPhone should work with S9 and S9+.

The fast wireless charging usually is advertised as 50% faster than standard wireless charging.   The fast wireless charging output power is typically about 7.5W.

Samsung Galaxy S9 and S9+ actually support up to 9w fast wireless charging. But it is only achievable in a very cool environment for a short period.

In a nutshell, you can charge Galaxy S9 with a wireless charging pad, which is not included in the Galaxy S9 box. When a standard wireless charging pad is used,  it will take about 3-4 hours to charge Galaxy S9 battery and about 3.5 to 5 hours to charge the S9+ battery.

The fast wireless charging pad can reduce the charging time about 50% compared to the standard wireless charging. But it is still slower than charging through the USB cable with the bundled wall charger.

How to charge Galaxy S9 battery with a wall charger

To charge Galaxy S9 battery (or S9+) with a USB cable, you may follow these steps.

Step 1:  Connect the USB cable to the wall charger (power adapter).

Any USB charger should work for Galaxy S9 and S9+. But you should only use a quality wall charger.

Don’t ruin your $800 phone with an $8 wall charger.

Step 2: Plug USB cable into Galaxy S9 (or S9+) USB port as shown below.

The USB port in Galaxy S9 and S9 is USB-C, which is symmetric.

So, you do not need to check the orientation of the USB connector.

Step 3: Plug the charger into the wall socket.

Step 4: Wait till Galaxy S9 or S9+ is fully charged.

Once you charge Galaxy S9 battery, it is better to charge it to full.

Also, you should refrain from using Galaxy S9 or S9+ when it is being charged.

The color of the LED in the top of Galaxy S9, and S9+ should turn from red to green once the battery is fully charged.

Step 5: Remove the USB cable form Galaxy S9 or S9+.

Step 6:  Power off the wall charger.

Wall chargers are not able to turn off themselves automatically. For safety considerations, it is better to unplug the wall charger or shut off the power supply to the charger.

How to use a wireless charging pad to charge Galaxy S9 battery?

You can use a standard or fast wireless charging pad to charge Galaxy S9 by following these steps:

Step 1:  Connect the power adapter or USB wall charger to the wireless charging pad

Most wireless charging pads require a power adapter or a USB wall charger. If the power adapter or wall charger is included, you should use them.

Some Samsung wireless charging pads don’t have a wall charger in the box. In this case, you should use the adaptive wall charger included in Galaxy S9 (or S9+) box.

Step 2: Plug the power adapter or wall charger into the wall socket.

Most wireless charging pads have one or more LEDs indicating the status of the pad.  You need to make sure the wireless charging pad is ready.

Step 3: Place Galaxy S9 or S9+ in the wireless charging pad

You need to place the center of Galaxy S9 or S9+’s back on the center of the wireless charging pad.

The wireless charging coil in Galaxy S9 and S9+ is close to the center of the back as explained in Galaxy S9 layout page.

You should also remove any metal accessories between the back of Galaxy S9 and the wireless charging pad.

Some third-party Galaxy S9 covers or cases may affect wireless charging. If this happens, you can try to remove the case or cover for Galaxy S9 and S9+.

All official Samsung cases and covers do NOT affect wireless charging.

Step 4: Wait till Galaxy S9 or S9+ is fully charged.

Once you charge Galaxy S9 battery, it is better to charge it to full.

You can know whether the Galaxy S9 battery is fully charged through one of the following methods:

• The LED indicator on the wireless charging pad.  For Samsung wireless charging pads, blue LED means charging, and green means fully charged.
• The LED color in the top of Galaxy S9 and S9+. Thr indicator LED is red when Galaxy S9 battery is being charged, and green when fully charged.
• Check Galaxy S9  lock screen.  Near the bottom of the lock screen, it states “charged” when Galaxy S9 battery is fully charged. Otherwise, it states “charging.”

Step 5: Remove Galaxy S9 or S9+ from the wireless charging pad.

When should you charge Galaxy S9 battery?

You should charge Galaxy S9 battery only when you need to do so.  It is not necessary to “top up.”

For example, after one-day work, before you go to bed, if the Galaxy S9 battery has about 60-70% capacity left, then you probably do not need to charge the battery unless you expect to use the phone heavily next day.

Of course, you can try to gauge the battery drain in one night and your typical usage.

The bottom lines are:

• It is not necessary to top up Galaxy S9 battery.
• If you can charge Galaxy S9 or S9+ before the battery is drained out, you do not need to charge it now.
• Never, never let the phone power off automatically due to a drained battery.

So, the key question here is when you can access the charger again.

If you are sure the battery can last till then, then why charge the battery now?

Should I charge Galaxy S9 battery for 8 hours before using the phone first time?

No, it is not necessary to charge the Galaxy S9 battery for 8 hours for the first time.

The old textbook is outdated.

How to disable fast charging and fast wireless charging for Galaxy S9 and S9+?

Fast charging and fast wireless charging should have a very marginal impact on Galaxy S9 battery lifespan.

Usually, it is NOT necessary to disable Galaxy S9 fast charging and fast wireless charging on Galaxy S9 or S9+. You should enjoy the convenience.

But if you still want to disable them, you can follow these steps.

Step 1:  Open Settings.

Step 2: Tap Device maintenance as shown below.

Step  3: Tap battery as shown above.

Step 4: Tap the menu key (3 vertical dots) as shown below.

Step 5: Tap advance settings as shown above.

Step 6: Tap the switch to enable or disable fast cable charging or fast wireless charging as shown below.

You can also disable fast wireless charging in Settings —Advanced features —Accessories as shown above.

How to choose a charger for Galaxy S9 and Galaxy S9+?

Please check this Galaxy S9 accessories guide on choosing a charger to charge Galaxy S9 and S9+.

Do you know how to charge Galaxy S9 battery? Do you have any questions about charging Galaxy S9 and S9+?

If you have any questions on charging Galaxy S9 battery for S9 or S9+, or if you have any questions about USB charging and wireless charging, please let us know in the comment box below.

The community will help you find the answer.

You can also share your Galaxy S9 unboxing experiences.

For the user guide for new features of Samsung Galaxy S9 and S9+, please check Galaxy S9 new features guides page.

For using Galaxy S9 and S9+, please check Galaxy S9 how-to guides page.

For using Galaxy S9 camera, please check Galaxy S9 camera guides page.

For accessories for Galaxy S9 and S9+, please check Galaxy S9 accessories guides page.

For the official Samsung Galaxy S9 and S9+ user guides (in PDF format), please check Galaxy S9 user guides page.