A popular and long-running theme on variety shows is zero-en seikatsu (no-yen living), an idea that goes beyond mere frugality to embrace a sort of charismatic philosophy. Since the March 11 earthquake and the attendant electrical power crisis, adherents of the zero-en lifestyle have been promoting the fact that sales outlets for the major mobile phone carriers all offer free battery-charging services to customers. Recently TV Tokyo's "Sunday Big Variety" profiled a female office worker who makes a fairly good side living clipping coupons and taking part in product promotional lotteries, but the aspect of her no-spending lifestyle she was most proud of was the fact that for the last five years she hadn't spent a single yen to recharge her phone.

Some people have to recharge their phones every day. How much does that normally cost if you do it at home? A number of Japanese bloggers have wondered the same thing. Apparently, it requires up to 10 watts of electricity per hour to recharge a cell phone, and the fee for household electricity is about ¥20 for 1 kilowatt per hour. Therefore, if it takes, say, four hours a day to recharge your phone, you will end up spending between ¥2 and ¥3 a month to do so. So that means the zero-en woman on the TV Tokyo show has, over five years, saved about ¥180.

To most people that won't mean much, and for sure the providers don't offer the recharging service for that reason. It's mainly for busy people who need an emergency recharge when they're not at home, and in that regard it's a real life saver since the alternative is buying one of those clunky, expensive supplemental batteries in a convenience store. Nevertheless, the employees of the service providers don't seem to know exactly how long it takes to recharge a cell phone. We went to several service centers that offer recharging and asked the employees how long it takes to recharge from zero, and only the DoCoMo staff was able to come up with a consistent, credible number: 2 hours. An au representative told us she didn't know how long it took but most customers spent 30 minutes; while Softbank said only 20 minutes.