Originally Posted by BrianG

Like I said, it shouldn't - at least not much. Typical fans should not pull enough current to affect runtime drastically like that. I would run without them on a cool day and see if it really is the fans that are causing your issues.

Judging by your other thread about your IBs, it sounds like your batteries may be the culprit since you are putting only 2800mAh back into a 4200mAh pack. Right there, your runtime is drastically reduced. If your fans were causing it, the charger would still be putting about 4.2Ah back into the packs.