If you rely on your smartphone and other mobile devices, the last thing you want to see before the end of your day is a low battery warning. But if you slip a TravelCard into your wallet, you have 1,500mAh of extra juice that’ll top up your devices when you need it most.

And thanks to Cult of Android Deals, you can get yours for just $29 for a limited time.

The TravelCard is sleek, slim, and perfect for an on-the-go lifestyle. Just charge it up, slip it inside your wallet or your purse, and it’s ready to charge up your smartphone, tablet, and other gadgets when they get low on power.

The TravelCard has a micro USB cable conveniently built-in, and it’s compatible with almost every Android-powered device you can buy. It’ll even charge handheld consoles like the PS Vita, and many digital cameras.

TravelCard is normally priced at $39, but for a limited time only, you can get it for just $29 through Cult of Android Deals.