Please, correct my essay.

If I could develop something new, I’d like to develop a portable battery, which could be used for any portable item such as a cellular phone, i-pod or a game player. These days, we have got many chances to carry portable items with batteries when we go out. It would be inconvenient more or less if we were short of battery for items during using those. However, if I had battery available to any portable item, I don’t have to worry about shortage of its battery. The item would enable me to keep using cellular phone if I were short of battery of it for long talk with friends.