Mobile phone charging

Hello,

Are mobile phone charging facilities available at JR stations or convenience stores in Japan?

If you have a phone by one of the local mobile carriers, meaning, Softbank, au, or Docomo, then you can walk into their shops in town and use their chargers. But in JR stations, I believe not, and in convenience stores you can buy portable chargers (the type you stick regular batteries into) for certain models.

Pay charging stations (for local carriers) are also available at some stations and stores. A small battery based recharger like AK mentioned is quite a bit more convenient though.

But what model phone will you be charging, and are you just looking to top up after a long day out, or are you looking for a primary means of charging your phone while travelling?

I have a Softbank phone (prepaid), and I'm basically looking for a way to keep it charged while travelling; I'm spending a couple of nights on night buses, which is why I asked.
But your answers have given me some idea, so thanks very much. :)

like AK said, the portable battery charger, cost 998 yen, come with 2xAA battery (easily replaceable) pack with detachable USB charger cable (you can charge it through computer/laptob USB port).

make sure you buy the charger pack (998yen) where the cover can be open for you to change your batteries, not the cheaper one 698yen,where the cover is closed shut tightly, you might break it if you force open it.

some stations have those coin operated PC where you can surf internet, you can use the PC USB port to charge you phone FREE of charge.

Then a portable battery charger will probably be most convenient. As mentioned, they can be purchased from convenience stores and come in two versions: one time use, and a version with replaceable batteries. Make sure to purchase one meant to charge Softbank phones, and note that they don't usually come with a usb cord. Here's some examples of what they look like:

http://search.rakuten.co.jp/search/mall?

some stations have those coin operated PC where you can surf internet, you can use the PC USB port to charge you phone FREE of charge.

I've seen coin operated internet kiosks at the airports, but I don't think they are very widespread at train/bus stations in Japan. Where have you seen them?