Fan only draws 0.25A @ 12VDC, so virtually no drain on Odyssey battery.
I have the exact same fan and used it the last 2 times that I flew and I have to say IT WORKS..lots of hot air coming out out of that door!
Also I agree,the battery had near zero discharge after 15 min,
Personally, I like this 10 min mod and I'm going to keep using this little fan.
I've never had vapor lock on my 12 but I know this cant hurt.
Thanks and love this forum.