My VEC1093DBD made horrible noises when first started, but then settled down. I took it apart and it was the fan being loose in its housing and buzzing. No problem with the actual cooling or charging.
I got another fan and mounted it outside the same vent with its wire pair running inside the vent spliced to original's wires. Totally quiet that way.
There was then an "issue" where I had the fan sucking instead of blowing or whichever, can't remember. Had to re-mount it the other way around. No problem after that!
Love my now quiet VEC1093DBD