We've all been in the situation where our smartphone is running out of battery power while we're far from home and sorely in need of a charge. It always seems to happen at the least opportune moment, when we're waiting for that important call, that crucial email from work, or using our GPS to navigate some unknown territory.

Back in the day of the flip phone, this quandary could be solved by carrying around an extra battery. The batteries weren't too heavy or bulky, and could easily be popped in and out of the back of the phone for a quick recharge. Nowadays, however, with many smartphones and most tablets having their batteries built-in to the device, a spare battery is not always an option.

These days, many people carry chargers around with them and search for an outlet to reignite their device. Besides the inconvenience and embarrassment of having to beg someone to plug your phone into their wall, you still have to wait for the device to charge.

Enter the Mighty Power Wallet and Mighty Purse, available at Firebox.com. Both contain a slim battery sewn into the leather of the item, along with a micro-USB cable. The user simply plugs the cable into their smartphone or other mobile device and allows it some time to charge. Though charging time varies according to device, the makers claim it can fully charge a fully drained iPhone 6 to 100 percent in two-and-a-half hours.

A company spokesman stated : "The battery is 3000 mAh and is placed inside the wallet -- it is well-concealed and doesn't take up much room. It charges your phone on the go and you shouldn't need to buy a new battery." If you do, however, be warned that since it is sewn into the product, you'll either have to buy a whole new wallet or know a good seamstress.

If your smartphone, like the iPhone 6, doesn't have a micro USB port, you'll need an additional adapter to charge it. And also be aware that you won't have any luck using the Power Wallet or Mighty Purse unless you also charge the battery within the products before you take them with you.

The wallet costs about $117 U.S. dollars, and is sized to fit in a pants pocket at 4 inches wide, 3.5 inches long and an inch thick (that's before you stuff it with your own cash and credit cards). The clutch purse for women costs about $140 U.S. dollars and comes in black, gold, pink and purple. Airmail and courier service delivery is available from the U.K. office.

Mighty Wallet® is a registered trademark of Dynomighty Design, Inc., which is not associated with the products described in this article.