Tongues, Our Supernatural Prayer Language

In writing to the church at Corinth, Paul encouraged them to continue the practice of speaking with other tongues in their worship of God and in their prayer lives as a means of spiritual edification.
Greek language scholars tell us that we have a word in our modern vernacular, which is closer to the meaning of the original than the word "edified."
That word is "charge" - as used in connection with charging a battery. Therefore we could paraphrase this verse, "He that speaketh in an unknown tongue edifies, charges, builds himself up like a battery."