oh hello there!! i am currently running a single 12v fan off a 9v battery. while it usually lasts through a full con weekend, it is completely inconsistent with fog prevention (i always pair with rain-x anti-fog on my face shield anyway), so i am looking to improve airflow. i plan to cut out the cheek hose area on the inside and make slashes through the hoses themselves, and i would like to place one fan on each side (one for air in, one for air out). i would like to get another fan, but don't want to install another battery. would it be possible to run two 5v fans off a single 9v battery? (from the perspective of an electronics n00b, it seems like it should be better, since i'd be drawing 10v instead of 12v, but i'm sure that logic is fatally flawed somewhere.)
sorry if this has been asked before, but i did use the search feature, and did not find the answer.
If the circuit is run correctly, you can run 2 5v fans off of 1 9v battery. The only problem with cutting holes in those vents is light getting into your helmet. If light gets in your helmet, it will be a lot easier to see though your visor, which is not cool off you ask me. I plan on running about 4 fans in my helmet when everything is said and done. I sweat more than the average person, so air movement will be very important.
Fyi most are about 7.5 ish volts. 6 cells .. the good lith ones are 9.