I haven't done any measurements on this yet, but I've had the I455 phone running 24/7 off the 2 port no data module. I've gone out to the car after 24 hours and had no noticeable affect on the battery, and I have a big motor to turn over. I'll be checking battery voltage levels later today and for the next 1-2 days as I'm letting the car sit (I'll prolly change the oil on Tuesday though, so I'll be cranking her back up then (well hopefully :p )).

