How to Charge Another Phone With Your Phone

Charging one phone using another sounds like a niche trick, but it's increasingly built into modern smartphones as a legitimate feature. Whether your friend's battery just died or you're in a pinch without a wall adapter, phone-to-phone charging is genuinely possible — though how well it works depends heavily on the devices involved.

What Is Phone-to-Phone Charging?

Phone-to-phone charging uses a feature called reverse wireless charging or wireless PowerShare, depending on the manufacturer. It turns your phone's back into a wireless charging pad, letting it transmit power to another device placed on top of it.

This works through the same Qi wireless charging standard used by conventional charging pads. Your phone essentially acts as a transmitter rather than a receiver, pulling from its own battery to push power into another device.

There's also a wired version: some phones support USB OTG (On-The-Go), which lets you connect two phones with a cable and have one supply power to the other. This is a different mechanism entirely and works on different hardware.

Wireless Phone-to-Phone Charging: How It Works

When reverse wireless charging is active, your phone's internal coil reverses its role. Instead of receiving an electromagnetic field from an external pad, it generates one. Any Qi-compatible device placed on the back of your phone — another smartphone, wireless earbuds, or a smartwatch — can draw power from it.

Key requirements:

• Your phone must explicitly support reverse wireless charging (not all do)
• The device being charged must support Qi wireless charging
• Both devices need to be properly aligned for the coil to connect

To activate it, you typically go into Settings → Battery (or search for "wireless PowerShare" / "reverse charging") and toggle it on. The receiving device just needs to be placed flat on the back of your phone.

⚡ One important caveat: reverse wireless charging is slow by design. Most implementations transfer power at around 3W to 5W — far below the fast charging speeds you'd get from a wall adapter. It's a convenience feature, not a speed solution.

Wired Phone-to-Phone Charging via USB OTG

If your phone supports USB OTG, you can use a cable to charge another device directly. This requires:

• A USB OTG adapter or a USB-C to USB-C cable (depending on ports)
• The source phone to have USB OTG host mode enabled or available
• The source phone to supply enough voltage to act as a power host

Not every phone supports acting as a power source over USB OTG. Some only support data transfer or charging into the phone, not out of it. Android devices vary significantly here, and iPhones using Lightning ports don't support this at all in the traditional sense — though USB-C iPhones (iPhone 15 and later) do support limited wired output.

Which Phones Support This?

Support for reverse wireless charging is concentrated in flagship and upper-mid-range Android devices. Samsung's Galaxy S and Z series, Huawei, Xiaomi, and OPPO devices have included it for several years. Google's Pixel line added it in more recent generations.

Budget Android phones and most mid-range devices frequently omit this feature to reduce cost and component complexity.

For iPhones, the situation is different. Apple has not included reverse wireless charging in any iPhone model as of current releases. iPhones can receive Qi charging but cannot transmit it. The USB-C transition in the iPhone 15 lineup did introduce wired accessory charging capability, which is a limited form of power output — but it's not the same as full reverse wireless charging.

🔋 If you're unsure whether your phone supports either feature, the clearest method is checking your phone's spec sheet under the battery or connectivity section, or searching your model name + "reverse wireless charging" or "USB OTG host."

What Affects How Useful This Actually Is

Even if your phone technically supports reverse wireless charging, how practical it is depends on several variables:

Your phone's battery size. A phone with a 4,000 mAh battery giving up charge to another device will drain quickly. Using this feature on a phone that's already at 50% or below may leave you with two half-charged phones.

The receiving device's efficiency. Wireless charging has inherent energy loss compared to wired charging. Some of the power transferred becomes heat rather than stored energy, meaning the actual charge delivered is less than what your phone expends.

Your use case. A quick top-up to get someone's phone to 10% so they can make a call is a very different scenario from trying to meaningfully charge a phone from 20% to 80%.

Environmental factors. Phone cases, alignment, and temperature all affect wireless transfer efficiency. A thick case on either device can interrupt the connection entirely.

The Variables That Matter for Your Situation

The gap between "this feature exists" and "this feature is useful for me" is significant. Whether reverse charging or USB OTG is worth relying on depends on which phones are involved, what scenarios you're trying to cover, and how frequently you'd need it.

Someone with a flagship Samsung and a Qi-compatible device will have a different experience than someone trying to do this with a budget phone or an iPhone. The technical floor for this feature to work at all is higher than most people expect — and once it works, the practical ceiling (speed and capacity) is lower than most people hope.

Your own battery habits, the devices in your household, and how often you're actually without a charger are the factors that determine whether this is a reliable fallback or a one-time curiosity. 📱