2010 Malibu won't crank

[Orpheus1951]

Our 2010 Malibu didn't turn over despite the battery being charged and no previous problems. Mechanic tested and stewed awhile, then disconnected the battery leads and held them together for a minute. Reconnecting the leads the car started right up, mechanic explaining something about capacitors needing to drain, and this problem might not happen again. Less than a week later it did. The same solution worked. Anyone with a clue about what's going on?