Battery shows X icon, erratically!

Hi : My mac book air early 2013 has 4 months. Everything was fine until this week. Battery started to show X icon in status bar erratically. Tried SMC restart, a few times it fixed the problem, most of the times it does not. It seems like a false electrical contact (some times fine, some times not working).

When showing the X icon it will only work if connected to the charger. When it switches back to normal, it shows the right battery charge (more or less as it was before showing the X icon).

Warranty is still valid, so I will take it to the store and let you know what they say.