Why is Charging So Slow in the Car?

Charging your phone in the car may be slower than charging it with a wall charger for various reasons:

Charging in the car can be slow due to a combination of factors such as lower power output from car USB ports or chargers, use of non-optimized or low-quality charging cables, running power-intensive apps while charging, and extreme temperature conditions, but using a high-quality charger and cable compatible with you.

1. Lower Power Output

Car chargers often have a lower power output than wall chargers. Wall chargers can deliver more power (typically around 18-25 watts or higher for newer models), while car chargers are usually limited to around 12-24 watts.

2. Quality of the Car Charger

Not all car chargers are created equal. If a charger doesn't support your phone's fast charging capabilities or has a lower wattage output, it will charge the phone more slowly.

3. USB Port Power

If you're charging your phone via a USB port in the car (such as the one in the stereo system), these ports often offer less power (around 0.5-2 amps) compared to a dedicated car charger plugged into the cigarette lighter.

4. Device Usage

If you're using your phone for navigation, music streaming, or other power-intensive tasks while charging, it will charge more slowly because it's using power at the same time.

5. Cable Quality

The quality of the charging cable can also affect charging speed. Cheap or damaged cables may not support fast charging or could be less efficient at conducting power.

6. Battery Condition

If your phone's battery is older or has reduced capacity, it might charge more slowly.

7. Car Battery Voltage

The voltage from your car's battery can fluctuate, especially if the engine is off. Running the engine often provides a more stable and higher voltage, which can lead to faster charging.

8. Temperature

Extreme temperatures, either hot or cold, can impact how quickly your phone can charge. It's best to charge the phone in moderate temperature conditions.

9. Multiple Devices

If your car charger has multiple ports and you're charging several devices at once, this can reduce the amount of power delivered to each device, resulting in slower charging speeds.

10. Charger Compatibility

If the car charger isn't fully compatible with your device, it may not be able to utilize the fastest charging method available for your phone.


Recommendations to improve car charging speed:

1. Use a High-Quality Charger

Invest in a high-quality car charger that supports fast charging standards compatible with your device, like Syncwire QC 3.0 (Quick Charge) or USB-PD (Power Delivery).

2. Upgrade Your Cable

Ensure you're using a high-quality cable that can support the fast charging capability of your charger and device.

3. Start the Engine

Keep the car engine running while charging, as the alternator will increase the voltage output and improve charging speed.

4. Avoid Use While Charging

Minimize the use of your device when it's charging to speed up the charging process.

5. Charge in Optimal Temperatures

Try to maintain an environment that isn't too hot or cold in the car, as extreme temperatures can slow down charging.

6. Dedicated Chargers

Use a dedicated car charger rather than the USB ports that come with the car for a faster charge.

7. Check Your Battery Health

If your phone has a significantly worn battery, consider replacing the battery to improve charging speed and overall battery life.

8. Disconnect Other Devices

If you're charging multiple devices, try to charge them one at a time, especially if you need one device charged quickly.

Following these recommendations can help ensure that your devices charge more quickly and efficiently in your car.