Does your smartphone need a little power boost? Mophie’s got a little booster just for that — on a keychain.

The tiny 1200 mAh Powerstation Keychain battery charger — 3-inch by 1.5-inch by 0.6-inch — perks up USB-C devices such as the Galaxy, Palm, and Google Pixel, as well as many USB-C- charging wireless headphones. (A Lightning cable model for iPhones is in the works).

Press the battery’s eject button, and it detaches from its carabiner, revealing a built in USB-C cable. Plug that into your device and extend battery life upwards of three hours, depending on the device. Four LED lights provide a power indicator. The battery recharges via USB-C cable (not included).

The 5-watt battery doesn’t have enough oomph to charge more demanding USB-C devices, such as the iPad Pro, which requires 18 watts. It won’t charge a drained battery 100 percent, and it’s not water-resistant, but at a mere 2 ounces, it’s worth hooking onto for an emergency zap.

Mophie Powerstation Keychain portable battery is $39.95 at mophie.com.