That's not good.But, less than 1 second after, a small ‘’Bam’’ come from the inside of the charger and the led closed.
It should be perfectly safe to power up the charger with no battery connected. However, you won't read anything at the output; it senses the battery (for correct polarity) before closing a relay inside to put voltage at the output.
Yes. A burning smell and a "bam" sound pretty much makes it definite.Do you think my charger is dead?
Something must have become damaged since manufacture, possibly during shipping. You'll have to get it repaired or replaced under warranty.