are you talking the fan on the charger or the PS? The Charger you can have on always or when needed. You do this by holding down the SEL-MOD button and changing the setting.
If its the PS your talking about, then i have no clue. LOL
I love the chargers fan, on auto it only turns on when discharging at 1 amp or more, and idk about charging cuz my balance connectors don't fit, I'm waiting on this: http://www.amainhobbies.com/product_...oducts_id/9755