YOu can also buy minutes on a plan that reduces the total cost per min down. I rented an iridium when I went to Alaska. I ordered two extra batteries so that if I needed to do some work (self employed) I could. Didn't really care about the cost of the minutes (no prepaid fees were $2.00 a minute). As it turned out I was stuck in a small town without a phone for 4 days (bad fires about 100 miles away completely covered the area and small planes wouldn't fly. I would check voice mail every 4 hrs. In doing so I found that the 3 batteries combined wouldn't last vut about 5 mins without charging. I was ticked off to say the least. Over all I think I spent about $115,$70 for the phone for two weeks (free shipping) and 45 for calls. I was able to get some work done (my billing rate easily covered the phone charges). A win, win for me.

That was about 3 years ago. I have since checked and the rates are even better. In hind site I would get it in advance (buy an extra week) testing out the batteries and replacing them if needed. They are rated like cell phone batteries, with x amount of talk time.