Doblet batteries on demand: Today SF, tomorrow the world!

You've probably never heard of Doblet, but if you live in San Francisco the name is going to become very important to you. The company is starting the first network of batteries on demand for recharging your smartphone, placing doblets (quick-charge battery packs) where you recharge -- in restaurants, bars and cafes.

The company now has doblets in about a hundred locations and expects to expand to about 1,000 Bay Area venues soon. Backed by Y Combinator, Doblet wants to expand to New York, Chicago, Boston, Miami and Toronto. Not only will your favorite watering hole or eatery have doblets available, but the company wants to place them at hotels, stadiums, airports, and in Lyft and Uber cars.

To use the service and find out where the nearest doblet is waiting for you, just download their free app. Once you've ordered a drink, you can pick up a charge for $3, a month of unlimited charging for $3, or a full year of charges for $30 -- available through in-app purchase. The doblet just plugs into your iPhone, and you can continue to use it while your phone gets recharged.

This seems like a wonderful idea, since many of us forget to carry external battery packs or charging cables with us, and it's annoying to have to be tied to an outlet. What are your thoughts on the service? Leave your comments below.