Battery light flashed once

Hello, That may be a loose battery terminal or the beginning of a failing wiring harness. First, look at your warranty. I think Mitsubishi stepped their warranty up over the last 5 years. If you don't see it happen for a while, that does not mean the problem is gone. Wiggle your battery cables and alternator wiring harness around while the engine is running. See if you can get that light to come on. If wiggling a part of the wire harness or the battery cable makes the light come on, that's where the problem is.