Fast-charging allows users to charge their phone’s battery from 0 to 100% in under an hour. But if you are that Samsung Galaxy user who prefers to slow charge your phones instead of fast charging, this is for you.
In this guide, we’ll explore the pros and cons of fast charging versus slow charging, look at how to enable slow charging on Samsung Galaxy phones, and provide some tips for minimizing battery degradation when slow charging.
Slow Charging vs. Fast Charging
Slow charging and fast charging represent two different philosophies when it comes to charging your Samsung Galaxy phone:
- Slow charging – Charges at slower speeds, typically 10W or lower. This reduces heat and battery wear to extend lifespan.
- Fast charging – Charges rapidly at 25W or more. This provides speed and convenience but can degrade batteries faster.
Understanding these key differences allows you to choose your charging method based on your priorities and usage habits.
Voltage and Amperage
On a technical level, slow and fast charging differ in the voltage and amperage provided:
- Slow charging uses standard 5V at 2A or lower amperage.
- Fast charging can use 9V or 12V at high amperage to charge faster.
Higher voltage and amperage generates more heat and strain during fast charging. Slow charging uses lower electrical current to reduce battery wear.
Charge Cycle Impact
Fast charging degrades each charge cycle more due to the increased heat and battery material stress. Slow charging preserves batteries for more cycles.
One study showed Samsung Galaxy batteries retained 95% capacity after 1 year of slow charging, but just 80% capacity after 1 year of fast charging 2-3 times per day.
Long-Term Battery Health
Slow charging promotes long-term battery health by minimizing capacity loss per charge cycle. The reduced heat prevents accelerated degradation over time.
Batteries fast charged daily from low percentages can lose up to 20% of original capacity in under a year. Slow charging maintains over 80% capacity even after hundreds of cycles.
The Pros and Cons of Fast Charging
First, let’s look at some of the potential benefits and drawbacks of fast charging:
Pros of Fast Charging
- Speed – Fast charging enables you to quickly top up your phone’s battery when you’re pressed for time.
- Convenience – With fast charging, you don’t need to remember to plug in your phone hours before you need it. You can simply plug it in and rapidly charge the battery when needed.
- Better for occasional charging – Fast charging applies increased voltage, so it can put more strain on the battery. This isn’t as much of an issue if you only occasionally fast charge.
Cons of Fast Charging
- Increased heat – Fast charging increases the amount of heat generated during charging, which can degrade the battery over time.
- Increased battery wear – The increased voltages and heat can degrade the battery more quickly compared to slow charging.
- Not great for frequent charging – If you frequently fast charge your phone from low percentages, it will likely degrade the battery capacity faster over time.
In summary, fast charging provides more speed and convenience, while potentially decreasing long-term battery lifespan compared to slow charging.
The Pros and Cons of Slow Charging
Now let’s look at some of the key advantages and disadvantages of slow charging your Samsung Galaxy phone:
Pros of Slow Charging
- Minimizes battery wear – Slow charging is gentler on the battery and causes less degradation over time.
- Generates less heat – Slow charging produces less heat, avoiding damage from overheating the battery.
- Safety – Slow charging has fewer electrical risks if the charger or cable is defective.
- Better for frequent charging – Slow charging is preferable if you frequently charge your phone from low battery levels.
Cons of Slow Charging
- Takes longer – Slow charging your phone battery from 0 to 100% can take 2-3 hours.
- Inconvenience – You need to remember to charge your phone well in advance of when you’ll need it.
- Not ideal for occasional charging – If you only charge periodically, slow charging means less time between charges.
In summary, slow charging maximizes long-term battery lifespan at the cost of speed and convenience. It’s best for frequent chargers who want their battery to last.
How to Enable Slow Charging on Samsung Galaxy Phones
Now that you understand the key differences between fast charging and slow charging, here are some steps to enable slow charging on various Samsung Galaxy phone models:
For Galaxy S10 and Newer
- Open the Settings app.
- Tap “Device care” or “Battery and device care” (name varies by model).
- Tap “Battery.”
- Tap the “Charging” header.
- Toggle “Fast cable charging” off.
This will disable fast charging and limit charging speed to a slower rate that is gentler on the battery.
For Galaxy S8/S9/Note 8/Note 9
- Open the Settings app.
- Tap “Device maintenance” or “Device care.”
- Tap “Battery.”
- Tap the 3-dot menu icon in the top-right corner.
- Tap “Advanced settings.”
- Toggle “Fast cable charging” off.
As with newer models, this disables fast charging on the Galaxy S8/S9 and Note 8/Note 9 series.
For Older Galaxy Models
Unfortunately Samsung did not include a straightforward way to disable fast charging on older Galaxy models like the S7 and below. However, there are a few options you can try:
- Use a lower wattage charger that only supports slower charging speeds.
- Buy a USB charging controller that regulates voltage and charging speed.
- Replace the battery if possible, as older batteries may not charge as slowly.
- Turn off the phone while charging to reduce heat and charging speed.
These options should allow you to mimic slower charging speeds on older Galaxy models.
Tips for Slow Charging Your Samsung Galaxy Phone
Here are some tips to help you get the most out of slow charging your Samsung Galaxy phone:
- Use the original charger and cable – Aftermarket cables may not support slow charging properly.
- Disable fast wireless charging – If your phone supports it, make sure fast wireless charging is off.
- Charge to only 80% frequently – Try not to frequently charge to 100%, as this increases battery wear.
- Avoid high temperatures – Don’t charge in hot environments like direct sunlight.
- Turn off phone during charging – This reduces battery heat and charging speed.
- Replace an old battery – An old battery will have a harder time with slow charging.
- Monitor capacity – Check battery health periodically to ensure slow charging is working.
Following these tips will help you maximize your battery lifespan while slow charging your Samsung Galaxy phone.
Frequently Asked Questions
Is slow charging bad for the battery?
No, slow charging is actually better for the long-term health of your phone’s battery compared to fast charging. Slow charging reduces heat generation and electrical stress on the battery, allowing it to last through more charge cycles before degrading.
Does slow charging reduce battery capacity?
Slow charging does not directly reduce battery capacity. In fact, by minimizing battery wear, slow charging helps maintain battery capacity over more charge cycles. However, an old battery that already has reduced capacity will charge more slowly.
Will slow charging damage my phone?
Slow charging will not damage your phone. It generates lower voltages and less heat than fast charging, so is safe for long-term use. The only downside is slower charging times.
How long should I slow charge for?
For optimal battery health, you should slow charge your phone whenever possible. Slow charge overnight or any time you do not need your phone to be charged quickly. There are no usage time limits when slow charging.
What charger wattage should I use?
For slow charging, use a charger with a wattage of 10W or lower. The original 5W chargers that came with Samsung phones are ideal. Higher wattages may still fast charge even with settings disabled.
Should I only slow charge to 80%?
It can help maximize battery lifespan if you regularly slow charge to only 80%. Avoiding constantly charging to 100% reduces strain. However, occasionally fully charging is fine.
How can I tell if my phone is slow charging?
If fast charging options are disabled in your phone’s settings, it should slow charge. You can confirm by looking at the estimated charging time, which should be 2-3 hours for a full charge if slow charging properly.
Maximizing Battery Longevity
Here are some additional tips for maximizing battery longevity on your Samsung Galaxy phone:
- Avoid letting your battery drain to 0% frequently.
- Don’t leave your phone exposed to high temperatures.
- Limit screen brightness when practical.
- Close background apps that drain battery.
- Avoid wireless charging which generates more heat.
- Replace an old battery that struggles to hold charge.
Combining these battery best practices with slow charging will help ensure your Samsung Galaxy phone’s battery lasts as long as possible.
When to Use Fast Charging
While slow charging is best for longevity, there are times when fast charging can be beneficial:
- If you forgot to charge and are pressed for time.
- Before long phone calls to quickly gain some charge.
- Before using phone heavily for navigation, video, games.
- If you have a removable battery and spare, you can fast charge the spare.
Occasional fast charging in these circumstances is fine. Just avoid fast charging daily from low percentages.
Charging Habits to Avoid
To maximize your Samsung Galaxy phone’s battery lifespan, here are some charging habits you should avoid:
- Fast charging too frequently, especially multiple times per day.
- Fast charging phones with old batteries that can’t handle the voltage.
- Leaving phones plugged in overnight after a full charge.
- Using generic fast chargers and cables that don’t regulate voltage properly.
- Charging with phones in very hot environments like direct sunlight.
- Letting your battery completely drain to 0% too often.
- Charging your phone too frequently throughout the day.
Avoiding these behaviors and sticking to slow overnight charging will give you the best battery lifespan.
Recognizing Your Battery is Degrading
Here are some signs that your Samsung Galaxy phone’s battery is degrading and needs to be replaced:
- Your charge doesn’t last as long between charges.
- You experience unexpected shutdowns with battery remaining.
- Your phone takes longer than usual to fully charge.
- You notice swelling or puffing of the battery.
- Your phone feels warmer while charging and in use.
- You see a message that charging is paused due to abnormal battery.
If you notice one or more of these symptoms of battery degradation, it’s a sign you should consider replacing your battery for optimal performance.
Extending Your Phone’s Lifespan
Here are some key tips for extending the usable lifespan of your Samsung Galaxy phone as long as possible:
- Use a protective case and screen protector.
- Keep the phone clean and dry.
- Charge the battery properly by following slow charging guidelines.
- Replace the battery after 2 years or when capacity drops.
- Perform software updates for latest features and security.
- Reboot your phone periodically to clear out glitches.
- Back up important data in case of failure.
Following best practices for hardware care, software maintenance, and battery charging will ensure you get the most life possible out of your Samsung Galaxy phone.
Slow Charging Settings
Samsung provides settings to enable slow charging on recent Galaxy models. Here are some additional details on these options:
- Fast cable charging – Disabling this limits the phone to slower 5V/2A charging.
- Fast wireless charging – Turn this off to limit wireless charging speed.
- Protect Battery – Can limit max charge to 85% to reduce wear.
You may need to disable both wired and wireless fast charging options to fully enforce slow charging speeds.
Third-Party Apps
Apps like Samsung’s Game Launcher and some third-party apps can also toggle fast charging on or off automatically in certain situations based on your preferences.
This allows you to configure fast charging only for certain apps or games when you want peak performance.
Automation
Using automation apps like Bixby Routines or Tasker, you could also automatically disable fast charging at night. This ensures slow charging when you sleep.
You can set locations, times, and other conditions to intelligently control fast charging versus slow charging.
How Heat Impacts Batteries
The increased heat from fast charging strains batteries in a few key ways:
- Accelerates chemical reactions that reduce capacity.
- Weakens the binder material holding battery together.
- Increases swelling and contraction that degrades cells.
- Forces the battery to work harder to cool down.
Slow charging generates far less heat, avoiding this accelerated battery wear. Lower temperatures preserve batteries for significantly more lifespan.
The 70% Rule
As a general guideline, try to keep your phone’s battery below 70°C or 158°F during charging. Temperatures above this accelerate capacity loss.
Fast charging can readily exceed this threshold, while slow charging generally keeps phones significantly cooler.
Monitoring Temperature
Some phones allow you to view current battery temperature in diagnostics or developer settings. Apps like Ampere or CPU-Z can also show you this.
Check temperature periodically when charging to ensure heat stays in check.
Comparing Charging Speeds
To demonstrate the drastic differences in charging speeds:
- Slow charging: 10% to 100% in 2-3 hours
- Fast charging: 10% to 100% in under 1.5 hours
- Super fast charging: 10% to 100% in under 1 hour
So super fast charging can charge in 1/3 the time of slow charging. The tradeoff is significantly accelerated battery wear.
Charging Efficiency
Slow charging is more efficient, converting over 90% of the charging current to stored energy in the battery.
Fast charging wastes more energy as heat due to electrical resistance, resulting in efficiency closer to 65-80%.
Diminishing Returns
The faster charging speeds provided diminishing returns – the difference between slow and fast charging times is much more pronounced than between fast and super fast.
Prioritize consistent charging over ultra-fast charging for the most efficient use of charge times.
Mitigating Fast Charging Damage
If you must fast charge frequently, here are some ways to help mitigate battery wear:
- Avoid fast charging to 100%. Stop around 90%.
- Use a lower wattage fast charger when possible.
- Take short 5-10 minute charging breaks instead of full 0-100%.
- Don’t fast charge when battery or phone is already warm.
- Avoid wireless charging which generates more heat.
While not as ideal as slow charging, these practices can help limit fast charging damage.
Case Temperature
If fast charging, check that your phone’s external case temperature stays below 40°C or 104°F. Higher temps indicate more internal heat.
Remove thick cases before charging to improve heat dissipation.
Ambient Temperature
Avoid fast charging in hot ambient environments, like in direct sunlight or a hot car. The combination with fast charging heat exacerbates damage.
Ideally fast charge in an air conditioned room to maximize heat dissipation.
Comparing Galaxy Models
Battery size and charging capabilities can vary across Samsung’s broad range of Galaxy phone models. Here’s how some key aspects compare:
| Model | Battery Size | Max Charge Speed |
| Galaxy S22 Ultra | 5,000 mAh | 45W |
| Galaxy S22/S22+ | 3,700/4,500 mAh | 25W |
| Galaxy S21 Series | 4,000/4,800 mAh | 25W |
| Galaxy S20 Series | 4,000/4,500 mAh | 25W |
| Galaxy S10 Series | 3,400/4,100 mAh | 15W |
| Galaxy S9/S9+ | 3,000/3,500 mAh | 15W |
Newer models tend to have larger batteries and faster potential charging. But you can slow charge any model for longevity.
Monitoring Health
Routinely check battery health stats in your phone’s settings or using apps like AccuBattery.
This allows you to identify capacity degradation and charging issues early.
Quarterly Checkups
Do a quarterly battery checkup to ensure your charging habits are optimal:
- Review battery usage by app.
- Examine battery capacity and cycle counts.
- Check for abnormal temperature increases.
- Run diagnostics and calibration if available.
Periodic battery maintenance preserves performance and lifespan.
Comparing Wireless and Wired Charging
Key differences between wireless charging and wired charging on Samsung Galaxy phones:
| Wireless Charging | Wired Charging | |
| Convenience | Just set phone on pad | Must plug in cable |
| Speed | Typically slower | Can be faster |
| Heat | Generates more heat | Stays cooler |
| Efficiency | More energy loss | Less loss, higher efficiency |
