I have an Automatic Link device plugged into my OBD II port at al times. I was told it draws 5.5 milliamps when the car is off. My question is, will this drain the battery a lot faster when the car is sitting? I know that the standard keyless entry system in the Prius puts a drain on the battery itself. What is the length of time that I should worry about disconnecting the 12v battery if I will not be driving the Prius? 2 weeks? 2 months? What make sense?
At 5.5mA, it would take a week for it to draw an amp. I would say 2 weeks should be safe, taking the rest of the car's systems into account.
Typical draw is 25-50mA from the car alone. An extra 5.5mA isn't going to make any difference until you are pushing the limits of the battery - ie letting it sit for many weeks.
Here is a good article on Prius battery discharge. 5.5 ma isn't going to make much difference in the calculation. Leaving a Toyota Prius Undriven
Just got back from 3 weeks vacation in Merida Yucatan, my car stay park at home and it was extremely cold -30C and it did start right away no hesitation of any kind.
I think the thing we have going for us is the Prius takes very little power to start up since no engine needs to crank over or anything. Once it's started, the hybrid battery takes over and will then start the engine.