This is a common question that many people have about their phone chargers. When you plug your phone charger into the wall but don’t have your phone connected to it, is it still drawing power? The short answer is yes, phone chargers do use a small amount of power when not connected to a phone. However, the amount is very minimal. In this article, we’ll take a deeper look at why phone chargers use power when not in use, how much power they use, and some tips for reducing the power draw.
Why Do Phone Chargers Use Power When Not In Use?
There are a couple reasons why phone chargers continue to draw power even when they are not actively charging a device:
- Standby power – All chargers use some electricity just to power the internal circuitry. This is known as standby power and allows the charger to detect when a device is connected and deliver power.
- Transformer – Phone chargers have a transformer inside that converts high voltage AC power from the wall into lower voltage DC power for your phone. The transformer draws power even when the output is not connected.
- LED indicator lights – Many chargers have LED lights to indicate when they are powered on. These lights use a small amount of electricity.
So in summary, the internal components, transformer, and indicator lights require a constant minimal power draw even when the charger is not actively charging a phone.
How Much Power Do Phone Chargers Use When Not In Use?
The amount of power a phone charger will use when not connected to a device depends on the charger, but is generally very small. Here are some typical power draw numbers for phone chargers when not in use:
- 5 watt iPhone charger – 0.1 watts
- 10 watt Samsung charger – 0.2 watts
- 15 watt fast charger – 0.5 watts
As you can see, even high-powered fast chargers only use about half a watt when not charging a device. For comparison, a typical LED light bulb uses between 5-15 watts.
Based on these numbers, if you did the math, a typical iPhone charger left plugged in but unused all year would only add around 1 kWh in annual power consumption. At an electricity rate of $0.12 per kWh, that’s less than 20 cents of energy costs for the whole year.
Tips for Reducing Power Draw
While the power draw from an unused phone charger is very small, there are some simple things you can do to further minimize standby power usage:
- Unplug the charger when not in use – Simply unplugging the charger from the wall outlet completely eliminates any power draw.
- Use a power strip – Plug chargers into a power strip that can be turned off to cut power to multiple devices.
- Replace old chargers – Newer chargers are more efficient and have lower standby power needs.
- Don’t overcharge – Unplug the charger once your phone is fully charged rather than leaving it plugged in indefinitely.
You can also look for chargers that are specifically designed to be energy efficient with ultra low standby power. These will typically advertise that feature on the packaging or in product descriptions.
Does Unplugging Chargers Really Save Electricity?
Based on the minimal power draw of phone chargers when unused, is it really worth worrying about unplugging them? Will it actually impact your electricity bill in a meaningful way?
Overall, for an individual unused phone charger, the electricity savings from unplugging it are negligible. However, when you multiply those tiny savings by the number of chargers in homes and offices around the world, it does start to add up.
Also, getting into the habit of unplugging chargers when not in use can lead to bigger energy savings when applied to other, more power hungry devices on standby mode.
| Device | Standby Power Draw |
|---|---|
| Cable box | 15-35 watts |
| Game console | 2-10 watts |
| Desktop computer | 2-15 watts |
As the table shows, items like cable boxes and game consoles use a lot more power when left plugged in and not in use. So getting in the habit with phone chargers can remind you to unplug these other devices too.
Conclusion
Phone chargers do continue to draw a small amount of power when left plugged into the wall without a phone connected. However, the amount of power is very minimal – generally less than half a watt. For an individual charger, this results in less than 20 cents of energy costs if left unused all year.
While the savings are small per charger, unplugging unused chargers and other devices on standby when possible can start to add up to more meaningful energy savings. Plus, it gets you in the habit of minimizing standby power use across all your devices.
So while you don’t need to obsess about unplugging an unused phone charger, doing so when convenient is certainly not a bad idea.